/*----------------------------------------------------------------------------/
/  FatFs - FAT file system module  R0.07e                    (C)ChaN, 2009
/-----------------------------------------------------------------------------/
/ FatFs module is a generic FAT file system module for small embedded systems.
/ This is a free software that opened for education, research and commercial
/ developments under license policy of following terms.
/
/  Copyright (C) 2009, ChaN, all right reserved.
/
/ * The FatFs module is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/   personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/-----------------------------------------------------------------------------/
/ Feb 26,'06 R0.00  Prototype.
/
/ Apr 29,'06 R0.01  First stable version.
/
/ Jun 01,'06 R0.02  Added FAT12 support.
/                   Removed unbuffered mode.
/                   Fixed a problem on small (<32M) partition.
/ Jun 10,'06 R0.02a Added a configuration option (_FS_MINIMUM).
/
/ Sep 22,'06 R0.03  Added f_rename().
/                   Changed option _FS_MINIMUM to _FS_MINIMIZE.
/ Dec 11,'06 R0.03a Improved cluster scan algorithm to write files fast.
/                   Fixed f_mkdir() creates incorrect directory on FAT32.
/
/ Feb 04,'07 R0.04  Supported multiple drive system.
/                   Changed some interfaces for multiple drive system.
/                   Changed f_mountdrv() to f_mount().
/                   Added f_mkfs().
/ Apr 01,'07 R0.04a Supported multiple partitions on a physical drive.
/                   Added a capability of extending file size to f_lseek().
/                   Added minimization level 3.
/                   Fixed an endian sensitive code in f_mkfs().
/ May 05,'07 R0.04b Added a configuration option _USE_NTFLAG.
/                   Added FSInfo support.
/                   Fixed DBCS name can result FR_INVALID_NAME.
/                   Fixed short seek (<= csize) collapses the file object.
/
/ Aug 25,'07 R0.05  Changed arguments of f_read(), f_write() and f_mkfs().
/                   Fixed f_mkfs() on FAT32 creates incorrect FSInfo.
/                   Fixed f_mkdir() on FAT32 creates incorrect directory.
/ Feb 03,'08 R0.05a Added f_truncate() and f_utime().
/                   Fixed off by one error at FAT sub-type determination.
/                   Fixed btr in f_read() can be mistruncated.
/                   Fixed cached sector is not flushed when create and close
/                   without write.
/
/ Apr 01,'08 R0.06  Added fputc(), fputs(), fprintf() and fgets().
/                   Improved performance of f_lseek() on moving to the same
/                   or following cluster.
/
/ Apr 01,'09 R0.07  Merged Tiny-FatFs as a buffer configuration option.
/                   Added long file name support.
/                   Added multiple code page support.
/                   Added re-entrancy for multitask operation.
/                   Added auto cluster size selection to f_mkfs().
/                   Added rewind option to f_readdir().
/                   Changed result code of critical errors.
/                   Renamed string functions to avoid name collision.
/ Apr 14,'09 R0.07a Separated out OS dependent code on reentrant cfg.
/                   Added multiple sector size support.
/ Jun 21,'09 R0.07c Fixed f_unlink() can return FR_OK on error.
/                   Fixed wrong cache control in f_lseek().
/                   Added relative path feature.
/                   Added f_chdir() and f_chdrive().
/                   Added proper case conversion to extended char.
/ Nov 03,'09 R0.07e Separated out configuration options from ff.h to ffconf.h.
/                   Fixed f_unlink() fails to remove a sub-dir on _FS_RPATH.
/                   Fixed name matching error on the 13 char boundary.
/                   Added a configuration option, _LFN_UNICODE.
/                   Changed f_readdir() to return the SFN with always upper
/                   case on non-LFN cfg.
/---------------------------------------------------------------------------*/

#include "ff.h"			/* FatFs configurations and declarations */
#include "diskio.h"		/* Declarations of low level disk I/O functions */


/*--------------------------------------------------------------------------

   Module Private Definitions

---------------------------------------------------------------------------*/

#if _FATFS != 0x007E
#error Wrong include file (ff.h).
#endif

#if _FS_REENTRANT
#if _USE_LFN == 1
#error Static LFN work area must not be used in re-entrant configuration.
#endif
#define	ENTER_FF(fs)		{ if (!lock_fs(fs)) return FR_TIMEOUT; }
#define	LEAVE_FF(fs, res)	{ unlock_fs(fs, res); return res; }

#else
#define	ENTER_FF(fs)
#define LEAVE_FF(fs, res)	return (res)

#endif

#define	ABORT(fs, res)		{ fp->flag |= FA__ERROR; LEAVE_FF((fs), (res)); }

#ifndef NULL
#define	NULL	0
#endif

/* Name status flags */
#define NS			11		/* Offset of name status byte */
#define NS_LOSS		0x01	/* Out of 8.3 format */
#define NS_LFN		0x02	/* Force to create LFN entry */
#define NS_LAST		0x04	/* Last segment */
#define NS_BODY		0x08	/* Lower case flag (body) */
#define NS_EXT		0x10	/* Lower case flag (ext) */
#define NS_DOT		0x20	/* Dot entry */




/*--------------------------------------------------------------------------

   Private Work Area

---------------------------------------------------------------------------*/

#if _DRIVES < 1 || _DRIVES > 9
#error Number of drives must be 1-9.
#endif
static
FATFS *FatFs[_DRIVES];	/* Pointer to the file system objects (logical drives) */

static
WORD Fsid;				/* File system mount ID */

#if _FS_RPATH
static
BYTE Drive;				/* Current drive */
#endif


#if _USE_LFN == 1	/* LFN with static LFN working buffer */
static
WCHAR LfnBuf[_MAX_LFN + 1];
#define	NAMEBUF(sp,lp)	BYTE sp[12]; WCHAR *lp = LfnBuf
#define INITBUF(dj,sp,lp)	dj.fn = sp; dj.lfn = lp

#elif _USE_LFN > 1	/* LFN with dynamic LFN working buffer */
#define	NAMEBUF(sp,lp)	BYTE sp[12]; WCHAR lbuf[_MAX_LFN + 1], *lp = lbuf
#define INITBUF(dj,sp,lp)	dj.fn = sp; dj.lfn = lp

#else				/* No LFN */
#define	NAMEBUF(sp,lp)	BYTE (sp)[12]
#define INITBUF(dj,sp,lp)	(dj).fn = (sp)

#endif




/*--------------------------------------------------------------------------

   Module Private Functions

---------------------------------------------------------------------------*/


/*-----------------------------------------------------------------------*/
/* String functions                                                      */
/*-----------------------------------------------------------------------*/

/* Copy memory to memory */
static void mem_cpy (void* dst, const void* src, int cnt) {
    char *d = (char*)dst;
    const char *s = (const char *)src;
    while (cnt--)
    {
        *d++ = *s++;
    }
}

/* Fill memory */
static void mem_set (void* dst, int val, int cnt) {
    char *d = (char*)dst;
    while (cnt--)
    {
        *d++ = (char)val;
    }
}

/* Compare memory to memory */
static int mem_cmp (const void* dst, const void* src, int cnt) {
    const char *d = (const char *)dst, *s = (const char *)src;
    int r = 0u;
    while(cnt--)
    {
        r = *d++ - *s++;
        if (0u != r)
            break;
    }
    return r;
}

/* Check if chr is contained in the string */
static int chk_chr (const char* str, int chr) {
    while ((*str != chr) && (*str))
    {
        str++;
    }
    return *str;
}



/*-----------------------------------------------------------------------*/
/* Request/Release grant to access the volume                            */
/*-----------------------------------------------------------------------*/
#if _FS_REENTRANT

static
BOOL lock_fs (
    FATFS *fs		/* File system object */
)
{
    return ff_req_grant(fs->sobj);
}


static
void unlock_fs (
    FATFS *fs,		/* File system object */
    FRESULT res		/* Result code to be returned */
)
{
    if (res != FR_NOT_ENABLED &&
        res != FR_INVALID_DRIVE &&
        res != FR_INVALID_OBJECT &&
        res != FR_TIMEOUT) {
        ff_rel_grant(fs->sobj);
    }
}
#endif



/*-----------------------------------------------------------------------*/
/* Change window offset                                                  */
/*-----------------------------------------------------------------------*/

static
FRESULT move_window (
    FATFS *fs,		/* File system object */
    DWORD sector	/* Sector number to make appearance in the fs->win[] */
)					/* Move to zero only writes back dirty window */
{
    DWORD wsect;


    wsect = fs->winsect;
    if (wsect != sector) {	/* Changed current window */
#if !_FS_READONLY
        if (fs->wflag) {	/* Write back dirty window if needed */
            if (disk_write(fs->drive, fs->win, wsect, 1u) != RES_OK)
                return FR_DISK_ERR;
            fs->wflag = 0u;
            if (wsect < (fs->fatbase + fs->sects_fat)) {	/* In FAT area */
                BYTE nf;
                for (nf = fs->n_fats; nf > 1u; nf--) {	/* Reflect the change to all FAT copies */
                    wsect += fs->sects_fat;
                    disk_write(fs->drive, fs->win, wsect, 1u);
                }
            }
        }
#endif
        if (sector) {
            if (disk_read(fs->drive, fs->win, sector, 1u) != RES_OK)
                return FR_DISK_ERR;
            fs->winsect = sector;
        }
    }

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* Clean-up cached data                                                  */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static
FRESULT sync (	/* FR_OK: successful, FR_DISK_ERR: failed */
    FATFS *fs	/* File system object */
)
{
    FRESULT res;


    res = move_window(fs, 0u);
    if (res == FR_OK) {
        /* Update FSInfo sector if needed */
        if ((fs->fs_type == FS_FAT32) && (fs->fsi_flag)) {
            fs->winsect = 0u;
            mem_set(fs->win, 0u, 512u);
            ST_WORD(fs->win+BS_55AA, 0xAA55u);
            ST_DWORD(fs->win+FSI_LeadSig, 0x41615252ul);
            ST_DWORD(fs->win+FSI_StrucSig, 0x61417272ul);
            ST_DWORD(fs->win+FSI_Free_Count, fs->free_clust);
            ST_DWORD(fs->win+FSI_Nxt_Free, fs->last_clust);
            disk_write(fs->drive, fs->win, fs->fsi_sector, 1u);
            fs->fsi_flag = 0;
        }
        /* Make sure that no pending write process in the physical drive */
        if (disk_ioctl(fs->drive, CTRL_SYNC, (void*)NULL) != RES_OK)
            res = FR_DISK_ERR;
    }

    return res;
}
#endif




/*-----------------------------------------------------------------------*/
/* FAT access - Read value of a FAT entry                                */
/*-----------------------------------------------------------------------*/


DWORD get_fat (	/* 0xFFFFFFFF:Disk error, 1:Internal error, Else:Cluster status */
    FATFS *fs,	/* File system object */
    DWORD clst	/* Cluster# to get the link information */
)
{
    UINT wc, bc;
    DWORD fsect;
        DWORD retVal = 0xFFFFFFFFul;


    if ((clst < 2u) || (clst >= fs->max_clust))	/* Range check */
        return 1u;

    fsect = fs->fatbase;
    switch (fs->fs_type) {
    case FS_FAT12 :
        bc = clst; bc += bc / 2u;
        if (move_window(fs, fsect + (bc / SS(fs)))) break;
        wc = fs->win[bc & (SS(fs) - 1u)]; bc++;
        if (move_window(fs, fsect + (bc / SS(fs)))) break;
        wc |= (WORD)fs->win[bc & (SS(fs) - 1u)] << 8u;
                retVal = (clst & 1u) ? (wc >> 4u) : (wc & 0xFFFu);
        break;

    case FS_FAT16 :
        if (move_window(fs, fsect + (clst / (SS(fs) / 2u)))) break;
        retVal =  LD_WORD(&fs->win[((WORD)clst * 2u) & (SS(fs) - 1u)]);
                break;

    case FS_FAT32 :
        if (move_window(fs, fsect + (clst / (SS(fs) / 4u)))) break;
        retVal =  LD_DWORD(&fs->win[((WORD)clst * 4u) & (SS(fs) - 1u)]) & 0x0FFFFFFFul;
                break;
    }

    return retVal;	/* An error occurred at the disk I/O layer */
}




/*-----------------------------------------------------------------------*/
/* FAT access - Change value of a FAT entry                              */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY

FRESULT put_fat (
    FATFS *fs,	/* File system object */
    DWORD clst,	/* Cluster# to be changed in range of 2 to fs->max_clust - 1 */
    DWORD val	/* New value to mark the cluster */
)
{
    UINT bc;
    BYTE *p;
    DWORD fsect;
    FRESULT res;


    if ((clst < 2u) || (clst >= fs->max_clust)) {	/* Range check */
        res = FR_INT_ERR;

    } else {
        fsect = fs->fatbase;
        switch (fs->fs_type) {
        case FS_FAT12 :
            bc = clst; bc += bc / 2u;
            res = move_window(fs, fsect + (bc / SS(fs)));
            if (res != FR_OK) break;
            p = &fs->win[bc & (SS(fs) - 1u)];
            *p = (clst & 1u) ? ((*p & 0x0Fu) | ((BYTE)val << 4u)) : (BYTE)val;
            bc++;
            fs->wflag = 1u;
            res = move_window(fs, fsect + (bc / SS(fs)));
            if (res != FR_OK) break;
            p = &fs->win[bc & (SS(fs) - 1u)];
            *p = (clst & 1u) ? (BYTE)(val >> 4u) : ((*p & 0xF0u) | ((BYTE)(val >> 8u) & 0x0Fu));
            break;

        case FS_FAT16 :
            res = move_window(fs, fsect + (clst / (SS(fs) / 2u)));
            if (res != FR_OK) break;
            ST_WORD(&fs->win[((WORD)clst * 2u) & (SS(fs) - 1u)], (WORD)val);
            break;

        case FS_FAT32 :
            res = move_window(fs, fsect + (clst / (SS(fs) / 4u)));
            if (res != FR_OK) break;
            ST_DWORD(&fs->win[((WORD)clst * 4u) & (SS(fs) - 1u)], val);
            break;

        default :
            res = FR_INT_ERR;
                        break;
        }
        fs->wflag = 1u;
    }

    return res;
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* FAT handling - Remove a cluster chain                                 */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static
FRESULT remove_chain (
    FATFS *fs,			/* File system object */
    DWORD clst			/* Cluster# to remove a chain from */
)
{
    FRESULT res;
    DWORD nxt;


    if ((clst < 2u) || (clst >= fs->max_clust)) {	/* Check the range of cluster# */
        res = FR_INT_ERR;

    } else {
        res = FR_OK;
        while (clst < fs->max_clust) {			/* Not a last link? */
            nxt = get_fat(fs, clst);			/* Get cluster status */
            if (nxt == 0u) break;				/* Empty cluster? */
            if (nxt == 1u) { res = FR_INT_ERR; break; }	/* Internal error? */
            if (nxt == 0xFFFFFFFFul) { res = FR_DISK_ERR; break; }	/* Disk error? */
            res = put_fat(fs, clst, 0u);			/* Mark the cluster "empty" */
            if (res != FR_OK) break;
            if (fs->free_clust != 0xFFFFFFFFul) {	/* Update FSInfo */
                fs->free_clust++;
                fs->fsi_flag = 1u;
            }
            clst = nxt;	/* Next cluster */
        }
    }

    return res;
}
#endif




/*-----------------------------------------------------------------------*/
/* FAT handling - Stretch or Create a cluster chain                      */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static
DWORD create_chain (	/* 0:No free cluster, 1:Internal error, 0xFFFFFFFF:Disk error, >=2:New cluster# */
    FATFS *fs,			/* File system object */
    DWORD clst			/* Cluster# to stretch. 0 means create a new chain. */
)
{
    DWORD cs, ncl, scl, mcl;


    mcl = fs->max_clust;
    if (clst == 0u) {		/* Create new chain */
        scl = fs->last_clust;			/* Get suggested start point */
        if ((scl == 0u) || (scl >= mcl)) scl = 1u;
    }
    else {					/* Stretch existing chain */
        cs = get_fat(fs, clst);			/* Check the cluster status */
        if (cs < 2u) return 1u;			/* It is an invalid cluster */
        if (cs < mcl) return cs;		/* It is already followed by next cluster */
        scl = clst;
    }

    ncl = scl;				/* Start cluster */
    for (;;) {
        ncl++;							/* Next cluster */
        if (ncl >= mcl) {				/* Wrap around */
            ncl = 2u;
            if (ncl > scl) return 0u;	/* No free cluster */
        }
        cs = get_fat(fs, ncl);			/* Get the cluster status */
        if (cs == 0u) break;				/* Found a free cluster */
        if ((cs == 0xFFFFFFFFul) || (cs == 1u))/* An error occurred */
            return cs;
        if (ncl == scl) return 0u;		/* No free cluster */
    }

    if (put_fat(fs, ncl, 0x0FFFFFFFul))	/* Mark the new cluster "in use" */
        return 0xFFFFFFFFul;
    if (clst != 0u) {					/* Link it to the previous one if needed */
        if (put_fat(fs, clst, ncl))
            return 0xFFFFFFFFul;
    }

    fs->last_clust = ncl;				/* Update FSINFO */
    if (fs->free_clust != 0xFFFFFFFFul) {
        fs->free_clust--;
        fs->fsi_flag = 1u;
    }

    return ncl;		/* Return new cluster number */
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Get sector# from cluster#                                             */
/*-----------------------------------------------------------------------*/


DWORD clust2sect (	/* !=0: Sector number, 0: Failed - invalid cluster# */
    FATFS *fs,		/* File system object */
    DWORD clst		/* Cluster# to be converted */
)
{
    clst -= 2u;
    if (clst >= (fs->max_clust - 2u)) return 0u;		/* Invalid cluster# */
    return clst * fs->csize + fs->database;
}




/*-----------------------------------------------------------------------*/
/* Directory handling - Seek directory index                             */
/*-----------------------------------------------------------------------*/

static
FRESULT dir_seek (
    DIR *dj,		/* Pointer to directory object */
    WORD idx		/* Directory index number */
)
{
    DWORD clst;
    WORD ic;


    dj->index = idx;
    clst = dj->sclust;
    if ((clst == 1u) || (clst >= dj->fs->max_clust))	/* Check start cluster range */
        return FR_INT_ERR;
    if ((!clst) && (dj->fs->fs_type == FS_FAT32))	/* Replace cluster# 0 with root cluster# if in FAT32 */
        clst = dj->fs->dirbase;

    if (clst == 0) {	/* Static table */
        dj->clust = clst;
        if (idx >= dj->fs->n_rootdir)		/* Index is out of range */
            return FR_INT_ERR;
        dj->sect = dj->fs->dirbase + idx / (SS(dj->fs) / 32);	/* Sector# */
    }
    else {				/* Dynamic table */
        ic = SS(dj->fs) / 32u * dj->fs->csize;	/* Entries per cluster */
        while (idx >= ic) {	/* Follow cluster chain */
            clst = get_fat(dj->fs, clst);				/* Get next cluster */
            if (clst == 0xFFFFFFFF) return FR_DISK_ERR;	/* Disk error */
            if ((clst < 2) || (clst >= dj->fs->max_clust))	/* Reached to end of table or int error */
                return FR_INT_ERR;
            idx -= ic;
        }
        dj->clust = clst;
        dj->sect = clust2sect(dj->fs, clst) + idx / (SS(dj->fs) / 32u);	/* Sector# */
    }

    dj->dir = dj->fs->win + (idx % (SS(dj->fs) / 32u)) * 32u;	/* Ptr to the entry in the sector */

    return FR_OK;	/* Seek succeeded */
}




/*-----------------------------------------------------------------------*/
/* Directory handling - Move directory index next                        */
/*-----------------------------------------------------------------------*/

static
FRESULT dir_next (	/* FR_OK:Succeeded, FR_NO_FILE:End of table, FR_DENIED:EOT and could not streach */
    DIR *dj,		/* Pointer to directory object */
    BOOL streach	/* FALSE: Do not stretch table, TRUE: Stretch table if needed */
)
{
    DWORD clst;
    WORD i;


    i = dj->index + 1;
    if ((!i) || (!dj->sect))	/* Report EOT when index has reached 65535 */
        return FR_NO_FILE;

    if (!(i % (SS(dj->fs) / 32u))) {	/* Sector changed? */
        dj->sect++;					/* Next sector */

        if (dj->clust == 0u) {	/* Static table */
            if (i >= dj->fs->n_rootdir)	/* Report EOT when end of table */
                return FR_NO_FILE;
        }
        else {					/* Dynamic table */
            if (((i / (SS(dj->fs) / 32u)) & (dj->fs->csize - 1u)) == 0u) {	/* Cluster changed? */
                clst = get_fat(dj->fs, dj->clust);				/* Get next cluster */
                if (clst <= 1u) return FR_INT_ERR;
                if (clst == 0xFFFFFFFFul) return FR_DISK_ERR;
                if (clst >= dj->fs->max_clust) {				/* When it reached end of dynamic table */
#if !_FS_READONLY
                    BYTE c;
                    if (!streach) return FR_NO_FILE;			/* When do not stretch, report EOT */
                    clst = create_chain(dj->fs, dj->clust);		/* Stretch cluster chain */
                    if (clst == 0u) return FR_DENIED;			/* No free cluster */
                    if (clst == 1u) return FR_INT_ERR;
                    if (clst == 0xFFFFFFFFul) return FR_DISK_ERR;
                    /* Clean-up streached table */
                    if (move_window(dj->fs, 0u)) return FR_DISK_ERR;	/* Flush active window */
                    mem_set(dj->fs->win, 0u, SS(dj->fs));			/* Clear window buffer */
                    dj->fs->winsect = clust2sect(dj->fs, clst);	/* Cluster start sector */
                    for (c = 0u; c < dj->fs->csize; c++) {		/* Fill the new cluster with 0 */
                        dj->fs->wflag = 1u;
                        if (move_window(dj->fs, 0u)) return FR_DISK_ERR;
                        dj->fs->winsect++;
                    }
                    dj->fs->winsect -= c;						/* Rewind window address */
#else
                    return FR_NO_FILE;			/* Report EOT */
#endif
                }
                dj->clust = clst;				/* Initialize data for new cluster */
                dj->sect = clust2sect(dj->fs, clst);
            }
        }
    }

    dj->index = i;
    dj->dir = dj->fs->win + (i % (SS(dj->fs) / 32u)) * 32u;

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* LFN handling - Test/Pick/Fit an LFN segment from/to directory entry   */
/*-----------------------------------------------------------------------*/
#if _USE_LFN
static
const BYTE LfnOfs[] = {1,3,5,7,9,14,16,18,20,22,24,28,30};	/* Offset of LFN chars in the directory entry */


static
BOOL cmp_lfn (			/* TRUE:Matched, FALSE:Not matched */
    WCHAR *lfnbuf,		/* Pointer to the LFN to be compared */
    BYTE *dir			/* Pointer to the directory entry containing a part of LFN */
)
{
    int i, s;
    WCHAR wc, uc;


    i = ((dir[LDIR_Ord] & 0xBFu) - 1u) * 13u;	/* Get offset in the LFN buffer */
    s = 0u; wc = 1u;
    do {
        uc = LD_WORD(dir+LfnOfs[s]);	/* Pick an LFN character from the entry */
        if (wc) {	/* Last char has not been processed */
            wc = ff_wtoupper(uc);		/* Convert it to upper case */
            if (i >= _MAX_LFN || wc != ff_wtoupper(lfnbuf[i++]))	/* Compare it */
                return FALSE;			/* Not matched */
        } else {
            if (uc != 0xFFFFul) return FALSE;	/* Check filler */
        }
    } while (++s < 13u);				/* Repeat until all chars in the entry are checked */

    if ((dir[LDIR_Ord] & 0x40u) && wc && lfnbuf[i])	/* Last segment matched but different length */
        return FALSE;

    return TRUE;					/* The part of LFN matched */
}



static
BOOL pick_lfn (			/* TRUE:Succeeded, FALSE:Buffer overflow */
    WCHAR *lfnbuf,		/* Pointer to the Unicode-LFN buffer */
    BYTE *dir			/* Pointer to the directory entry */
)
{
    int i, s;
    WCHAR wc, uc;


    i = ((dir[LDIR_Ord] & 0x3Fu) - 1u) * 13u;	/* Offset in the LFN buffer */

    s = 0u; wc = 1u;
    do {
        uc = LD_WORD(dir+LfnOfs[s]);			/* Pick an LFN character from the entry */
        if (wc) {	/* Last char has not been processed */
            if (i >= _MAX_LFN) return FALSE;	/* Buffer overflow? */
            lfnbuf[i++] = wc = uc;				/* Store it */
        } else {
            if (uc != 0xFFFFu) return FALSE;		/* Check filler */
        }
    } while (++s < 13u);						/* Read all character in the entry */

    if (dir[LDIR_Ord] & 0x40u) {				/* Put terminator if it is the last LFN part */
        if (i >= _MAX_LFN) return FALSE;	/* Buffer overflow? */
        lfnbuf[i] = 0u;
    }

    return TRUE;
}


#if !_FS_READONLY
static
void fit_lfn (
    const WCHAR *lfnbuf,	/* Pointer to the LFN buffer */
    BYTE *dir,				/* Pointer to the directory entry */
    BYTE ord,				/* LFN order (1-20) */
    BYTE sum				/* SFN sum */
)
{
    int i, s;
    WCHAR wc;

    dir[LDIR_Chksum] = sum;			/* Set check sum */
    dir[LDIR_Attr] = AM_LFN;		/* Set attribute. LFN entry */
    dir[LDIR_Type] = 0u;
    ST_WORD(dir+LDIR_FstClusLO, 0u);

    i = (ord - 1u) * 13u;				/* Get offset in the LFN buffer */
    s = wc = 0u;
    do {
        if (wc != 0xFFFFu) wc = lfnbuf[i++];	/* Get an effective char */
        ST_WORD(dir+LfnOfs[s], wc);	/* Put it */
        if (!wc) wc = 0xFFFFu;		/* Padding chars following last char */
    } while (++s < 13u);
    if (wc == 0xFFFFu || !lfnbuf[i]) ord |= 0x40u;	/* Bottom LFN part is the start of LFN sequence */
    dir[LDIR_Ord] = ord;			/* Set the LFN order */
}

#endif
#endif



/*-----------------------------------------------------------------------*/
/* Create numbered name                                                  */
/*-----------------------------------------------------------------------*/
#if _USE_LFN
void gen_numname (
    BYTE *dst,			/* Pointer to generated SFN */
    const BYTE *src,	/* Pointer to source SFN to be modified */
    const WCHAR *lfn,	/* Pointer to LFN */
    WORD num			/* Sequence number */
)
{
    char ns[8];
    int i, j;


    mem_cpy(dst, src, 11u);

    if (num > 5u) {	/* On many collisions, generate a hash number instead of sequential number */
        do num = (num >> 1u) + (num << 15u) + (WORD)*lfn++; while (*lfn);
    }

    /* itoa */
    i = 7u;
    do {
        ns[i--] = (num % 10u) + '0';
        num /= 10u;
    } while (num);
    ns[i] = '~';

    /* Append the number */
    for (j = 0u; j < i && dst[j] != ' '; j++) {
        if (IsDBCS1(dst[j])) {
            if (j == i - 1u) break;
            j++;
        }
    }
    do {
        dst[j++] = (i < 8u) ? ns[i++] : ' ';
    } while (j < 8u);
}
#endif




/*-----------------------------------------------------------------------*/
/* Calculate sum of an SFN                                               */
/*-----------------------------------------------------------------------*/
#if _USE_LFN
static
BYTE sum_sfn (
    const BYTE *dir		/* Ptr to directory entry */
)
{
    BYTE sum = 0u;
    int n = 11u;

    do sum = (sum >> 1u) + (sum << 7u) + *dir++; while (--n);
    return sum;
}
#endif




/*-----------------------------------------------------------------------*/
/* Directory handling - Find an object in the directory                  */
/*-----------------------------------------------------------------------*/

static
FRESULT dir_find (
    DIR *dj			/* Pointer to the directory object linked to the file name */
)
{
    FRESULT res;
    BYTE c, *dir;
#if _USE_LFN
    BYTE a, ord, sum;
#endif

    res = dir_seek(dj, 0u);			/* Rewind directory object */
    if (res != FR_OK) return res;

#if _USE_LFN
    ord = sum = 0xFFu;
#endif
    do {
        res = move_window(dj->fs, dj->sect);
        if (res != FR_OK) break;
        dir = dj->dir;					/* Ptr to the directory entry of current index */
        c = dir[DIR_Name];
        if (c == 0u) { res = FR_NO_FILE; break; }	/* Reached to end of table */
#if _USE_LFN	/* LFN configuration */
        a = dir[DIR_Attr] & AM_MASK;
        if (c == 0xE5u || ((a & AM_VOL) && a != AM_LFN)) {	/* An entry without valid data */
            ord = 0xFFu;
        } else {
            if (a == AM_LFN) {			/* An LFN entry is found */
                if (dj->lfn) {
                    if (c & 0x40u) {		/* Is it start of LFN sequence? */
                        sum = dir[LDIR_Chksum];
                        c &= 0xBFu; ord = c;	/* LFN start order */
                        dj->lfn_idx = dj->index;
                    }
                    /* Check validity of the LFN entry and compare it with given name */
                    ord = (c == ord && sum == dir[LDIR_Chksum] && cmp_lfn(dj->lfn, dir)) ? ord - 1u : 0xFFu;
                }
            } else {					/* An SFN entry is found */
                if (!ord && sum == sum_sfn(dir)) break;	/* LFN matched? */
                ord = 0xFFu; dj->lfn_idx = 0xFFFFu;	/* Reset LFN sequence */
                if (!(dj->fn[NS] & NS_LOSS) && !mem_cmp(dir, dj->fn, 11u)) break;	/* SFN matched? */
            }
        }
#else		/* Non LFN configuration */
        if ((!(dir[DIR_Attr] & AM_VOL)) && (!mem_cmp(dir, dj->fn, 11u))) /* Is it a valid entry? */
            break;
#endif
        res = dir_next(dj, FALSE);		/* Next entry */
    } while (res == FR_OK);

    return res;
}




/*-----------------------------------------------------------------------*/
/* Read an object from the directory                                     */
/*-----------------------------------------------------------------------*/
#if _FS_MINIMIZE <= 1
static
FRESULT dir_read (
    DIR *dj			/* Pointer to the directory object that pointing the entry to be read */
)
{
    FRESULT res;
    BYTE c, *dir;
#if _USE_LFN
    BYTE a, ord = 0xFFu, sum = 0xFFu;
#endif

    res = FR_NO_FILE;
    while (dj->sect) {
        res = move_window(dj->fs, dj->sect);
        if (res != FR_OK) break;
        dir = dj->dir;					/* Ptr to the directory entry of current index */
        c = dir[DIR_Name];
        if (c == 0u) { res = FR_NO_FILE; break; }	/* Reached to end of table */
#if _USE_LFN	/* LFN configuration */
        a = dir[DIR_Attr] & AM_MASK;
        if (c == 0xE5u || (!_FS_RPATH && c == '.') || ((a & AM_VOL) && a != AM_LFN)) {	/* An entry without valid data */
            ord = 0xFFu;
        } else {
            if (a == AM_LFN) {			/* An LFN entry is found */
                if (c & 0x40u) {			/* Is it start of LFN sequence? */
                    sum = dir[LDIR_Chksum];
                    c &= 0xBFu; ord = c;
                    dj->lfn_idx = dj->index;
                }
                /* Check LFN validity and capture it */
                ord = (c == ord && sum == dir[LDIR_Chksum] && pick_lfn(dj->lfn, dir)) ? ord - 1 : 0xFF;
            } else {					/* An SFN entry is found */
                if (ord || sum != sum_sfn(dir))	/* Is there a valid LFN? */
                    dj->lfn_idx = 0xFFFFu;		/* It has no LFN. */
                break;
            }
        }
#else		/* Non LFN configuration */
        if ((c != 0xE5u) && (_FS_RPATH || (c != '.')) && (!(dir[DIR_Attr] & AM_VOL)))	/* Is it a valid entry? */
            break;
#endif
        res = dir_next(dj, FALSE);				/* Next entry */
        if (res != FR_OK) break;
    }

    if (res != FR_OK) dj->sect = 0u;

    return res;
}
#endif



/*-----------------------------------------------------------------------*/
/* Register an object to the directory                                   */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static
FRESULT dir_register (	/* FR_OK:Successful, FR_DENIED:No free entry or too many SFN collision, FR_DISK_ERR:Disk error */
    DIR *dj				/* Target directory with object name to be created */
)
{
    FRESULT res;
    BYTE c, *dir;
#if _USE_LFN	/* LFN configuration */
    WORD n, ne, is;
    BYTE sn[12], *fn, sum;
    WCHAR *lfn;


    fn = dj->fn; lfn = dj->lfn;
    mem_cpy(sn, fn, 12u);

    if (_FS_RPATH && (sn[NS] & NS_DOT)) return FR_INVALID_NAME;	/* Cannot create dot entry */

    if (sn[NS] & NS_LOSS) {			/* When LFN is out of 8.3 format, generate a numbered name */
        fn[NS] = 0u; dj->lfn = NULL;			/* Find only SFN */
        for (n = 1u; n < 100u; n++) {
            gen_numname(fn, sn, lfn, n);	/* Generate a numbered name */
            res = dir_find(dj);				/* Check if the name collides with existing SFN */
            if (res != FR_OK) break;
        }
        if (n == 100u) return FR_DENIED;		/* Abort if too many collisions */
        if (res != FR_NO_FILE) return res;	/* Abort if the result is other than 'not collided' */
        fn[NS] = sn[NS]; dj->lfn = lfn;
    }

    if (sn[NS] & NS_LFN) {			/* When LFN is to be created, reserve reserve an SFN + LFN entries. */
        for (ne = 0u; lfn[ne]; ne++) ;
        ne = (ne + 25u) / 13u;
    } else {						/* Otherwise reserve only an SFN entry. */
        ne = 1;
    }

    /* Reserve contiguous entries */
    res = dir_seek(dj, 0u);
    if (res != FR_OK) return res;
    n = is = 0u;
    do {
        res = move_window(dj->fs, dj->sect);
        if (res != FR_OK) break;
        c = *dj->dir;				/* Check the entry status */
        if (c == 0xE5u || c == 0u) {	/* Is it a blank entry? */
            if (n == 0u) is = dj->index;	/* First index of the contiguous entry */
            if (++n == ne) break;	/* A contiguous entry that required count is found */
        } else {
            n = 0u;					/* Not a blank entry. Restart to search */
        }
        res = dir_next(dj, TRUE);	/* Next entry with table stretch */
    } while (res == FR_OK);

    if (res == FR_OK && ne > 1u) {	/* Initialize LFN entry if needed */
        res = dir_seek(dj, is);
        if (res == FR_OK) {
            sum = sum_sfn(dj->fn);	/* Sum of the SFN tied to the LFN */
            ne--;
            do {					/* Store LFN entries in bottom first */
                res = move_window(dj->fs, dj->sect);
                if (res != FR_OK) break;
                fit_lfn(dj->lfn, dj->dir, (BYTE)ne, sum);
                dj->fs->wflag = 1u;
                res = dir_next(dj, FALSE);	/* Next entry */
            } while (res == FR_OK && --ne);
        }
    }

#else	/* Non LFN configuration */
    res = dir_seek(dj, 0u);
    if (res == FR_OK) {
        do {	/* Find a blank entry for the SFN */
            res = move_window(dj->fs, dj->sect);
            if (res != FR_OK) break;
            c = *dj->dir;
            if ((c == 0xE5u) || (c == 0u)) break;	/* Is it a blank entry? */
            res = dir_next(dj, TRUE);		/* Next entry with table streach */
        } while (res == FR_OK);
    }
#endif

    if (res == FR_OK) {		/* Initialize the SFN entry */
        res = move_window(dj->fs, dj->sect);
        if (res == FR_OK) {
            dir = dj->dir;
            mem_set(dir, 0u, 32u);		/* Clean the entry */
            mem_cpy(dir, dj->fn, 11u);	/* Put SFN */
            dir[DIR_NTres] = *(dj->fn+NS) & (NS_BODY | NS_EXT);	/* Put NT flag */
            dj->fs->wflag = 1u;
        }
    }

    return res;
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Remove an object from the directory                                   */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY && !_FS_MINIMIZE
static
FRESULT dir_remove (	/* FR_OK: Successful, FR_DISK_ERR: A disk error */
    DIR *dj				/* Directory object pointing the entry to be removed */
)
{
    FRESULT res;
#if _USE_LFN	/* LFN configuration */
    WORD i;

    i = dj->index;	/* SFN index */
    res = dir_seek(dj, (WORD)((dj->lfn_idx == 0xFFFFu) ? i : dj->lfn_idx));	/* Goto the SFN or top of the LFN entries */
    if (res == FR_OK) {
        do {
            res = move_window(dj->fs, dj->sect);
            if (res != FR_OK) break;
            *dj->dir = 0xE5u;			/* Mark the entry "deleted" */
            dj->fs->wflag = 1u;
            if (dj->index >= i) break;	/* When reached SFN, all entries of the object has been deleted. */
            res = dir_next(dj, FALSE);	/* Next entry */
        } while (res == FR_OK);
        if (res == FR_NO_FILE) res = FR_INT_ERR;
    }

#else			/* Non LFN configuration */
    res = dir_seek(dj, dj->index);
    if (res == FR_OK) {
        res = move_window(dj->fs, dj->sect);
        if (res == FR_OK) {
            *dj->dir = 0xE5u;			/* Mark the entry "deleted" */
            dj->fs->wflag = 1u;
        }
    }
#endif

    return res;
}
#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Pick a segment and create the object name in directory form           */
/*-----------------------------------------------------------------------*/

static
FRESULT create_name (
    DIR *dj,			/* Pointer to the directory object */
    const XCHAR **path	/* Pointer to pointer to the segment in the path string */
)
{
#ifdef _EXCVT
    static const BYTE cvt[] = _EXCVT;
#endif

#if _USE_LFN	/* LFN configuration */
    BYTE b, cf;
    WCHAR w, *lfn;
    int i, ni, si, di;
    const XCHAR *p;

    /* Create LFN in Unicode */
    si = di = 0u;
    p = *path;
    lfn = dj->lfn;
    for (;;) {
        w = p[si++];					/* Get a character */
        if (w < ' ' || w == '/' || w == '\\') break;	/* Break on end of segment */
        if (di >= _MAX_LFN)				/* Reject too long name */
            return FR_INVALID_NAME;
#if !_LFN_UNICODE
        w &= 0xFFu;
        if (IsDBCS1(w)) {				/* If it is a DBC 1st byte */
            b = p[si++];				/* Get 2nd byte */
            if (!IsDBCS2(b))			/* Reject invalid code for DBC */
                return FR_INVALID_NAME;
            //w = (w << 8) + b;
            else w = (w << 8u) + b;
        }
        w = ff_convert(w, 1u);			/* Convert OEM to Unicode */
        if (!w) return FR_INVALID_NAME;	/* Reject invalid code */
#endif
        if (w < 0x80u && chk_chr("\"*:<>\?|\x7F", w)) /* Reject illegal chars for LFN */
            return FR_INVALID_NAME;
        lfn[di++] = w;					/* Store the Unicode char */
    }
    *path = &p[si];						/* Return pointer to the next segment */
    cf = (w < ' ') ? NS_LAST : 0u;		/* Set last segment flag if end of path */
#if _FS_RPATH
    if ((di == 1u && lfn[di - 1u] == '.') || /* Is this a dot entry? */
        (di == 2u && lfn[di - 1u] == '.' && lfn[di - 2u] == '.')) {
        lfn[di] = 0;
        for (i = 0u; i < 11u; i++)
            dj->fn[i] = (i < di) ? '.' : ' ';
        dj->fn[i] = cf | NS_DOT;		/* This is a dot entry */
        return FR_OK;
    }
#endif
    while (di) {						/* Strip trailing spaces and dots */
        w = lfn[di - 1u];
        if (w != ' ' && w != '.') break;
        di--;
    }
    if (!di) return FR_INVALID_NAME;	/* Reject null string */

    lfn[di] = 0u;						/* LFN is created */

    /* Create SFN in directory form */
    mem_set(dj->fn, ' ', 11u);
    for (si = 0u; lfn[si] == ' ' || lfn[si] == '.'; si++) ;	/* Strip leading spaces and dots */
    if (si) cf |= NS_LOSS | NS_LFN;
    while (di && lfn[di - 1u] != '.') di--;	/* Find extension (di<=si: no extension) */

    b = i = 0u; ni = 8u;
    for (;;) {
        w = lfn[si++];					/* Get an LFN char */
        if (!w) break;					/* Break on end of the LFN */
        if (w == ' ' || (w == '.' && si != di)) {	/* Remove spaces and dots */
            cf |= NS_LOSS | NS_LFN; continue;
        }

        if (i >= ni || si == di) {		/* Extension or end of SFN */
            if (ni == 11u) {				/* Long extension */
                cf |= NS_LOSS | NS_LFN; break;
            }
            if (si != di) cf |= NS_LOSS | NS_LFN;	/* Out of 8.3 format */
            if (si > di) break;			/* No extension */
            si = di; i = 8u; ni = 11u;	/* Enter extension section */
            b <<= 2u; continue;
        }

        if (w >= 0x80u) {				/* Non ASCII char */
#ifdef _EXCVT
            w = ff_convert(w, 0u);		/* Unicode -> OEM code */
            if (w) w = cvt[w - 0x80u];	/* Convert extended char to upper (SBCS) */
#else
            w = ff_convert(ff_wtoupper(w), 0u);	/* Upper converted Unicode -> OEM code */
#endif
            cf |= NS_LFN;				/* Force create LFN entry */
        }

        if (_DF1S && w >= 0x100u) {		/* Double byte char */
            if (i >= ni - 1u) {
                cf |= NS_LOSS | NS_LFN; i = ni; continue;
            }
            dj->fn[i++] = (BYTE)(w >> 8u);
        } else {						/* Single byte char */
            if (!w || chk_chr("+,;[=]", w)) {		/* Replace illegal chars for SFN */
                w = '_'; cf |= NS_LOSS | NS_LFN;	/* Lossy conversion */
            } else {
                if (IsUpper(w)) {		/* ASCII large capital */
                    b |= 2u;
                } else {
                    if (IsLower(w)) {	/* ASCII small capital */
                        b |= 1u; w -= 0x20u;
                    }
                }
            }
        }
        dj->fn[i++] = (BYTE)w;
    }

    if (dj->fn[0] == 0xE5u) dj->fn[0] = 0x05u;	/* If the first char collides with deleted mark, replace it with 0x05 */

    if (ni == 8u) b <<= 2u;
    if ((b & 0x0Cu) == 0x0Cu || (b & 0x03) == 0x03u)	/* Create LFN entry when there are composite capitals */
        cf |= NS_LFN;
    if (!(cf & NS_LFN)) {						/* When LFN is in 8.3 format without extended char, NT flags are created */
        if ((b & 0x03u) == 0x01u) cf |= NS_EXT;	/* NT flag (Extension has only small capital) */
        if ((b & 0x0Cu) == 0x04u) cf |= NS_BODY;	/* NT flag (Filename has only small capital) */
    }

    dj->fn[NS] = cf;	/* SFN is created */
    return FR_OK;


#else	/* Non-LFN configuration */
    BYTE b, c, *sfn;
#if _FS_RPATH
        BYTE d;
#endif  /* C-STAT */
    int ni, si, i;
    const char *p;

    /* Create file name in directory form */
    sfn = dj->fn;
    mem_set(sfn, ' ', 11u);
    si = i = b = 0u; ni = 8u;
    p = *path;
#if _FS_RPATH
    if (p[si] == '.') { /* Is this a dot entry? */
        for (;;) {
            c = p[si++];
            if (c != '.' || si >= 3u) break;
            sfn[i++] = c;
        }
        if (c != '/' && c != '\\' && c > ' ') return FR_INVALID_NAME;
        *path = &p[si];									/* Return pointer to the next segment */
        sfn[NS] = (c <= ' ') ? NS_LAST | NS_DOT : NS_DOT;	/* Set last segment flag if end of path */
        return FR_OK;
    }
#endif
    for (;;) {
        c = p[si++];
        if ((c <= ' ') || (c == '/') || (c == '\\')) break;	/* Break on end of segment */
        if ((c == '.') || (i >= ni)) {
            if ((ni != 8u) || (c != '.')) return FR_INVALID_NAME;
            i = 8u; ni = 11u;
            b <<= 2u; continue;
        }
        if (c >= 0x80u) {				/* Extended char */
#ifdef _EXCVT
            c = cvt[c - 0x80u];			/* Convert extend char (SBCS) */
#else
            b |= 3u;						/* Eliminate NT flag if ext char is exist */
#if !_DF1S	/* ASCII only cfg */
            return FR_INVALID_NAME;
#endif
#endif
        }
#if _DF1S
        if (IsDBCS1(c)) {				/* DBC 1st byte? */
            d = p[si++];				/* Get 2nd byte */
            if (!IsDBCS2(d) || i >= ni - 1)	/* Reject invalid DBC */
                return FR_INVALID_NAME;
            sfn[i++] = c;
            sfn[i++] = d;
        } else
#endif  /* C-STAT */
                {						/* Single byte code */
            if (chk_chr(" \"*+,[=]|\x7F", c))	/* Reject illegal chrs for SFN */
                return FR_INVALID_NAME;
            if (IsUpper(c)) {			/* ASCII large capital? */
                b |= 2u;
            } else {
                if (IsLower(c)) {		/* ASCII small capital? */
                    b |= 1u; c -= 0x20u;
                }
            }
            sfn[i++] = c;
        }
    }
    *path = &p[si];						/* Return pointer to the next segment */
    c = (c <= ' ') ? NS_LAST : 0u;		/* Set last segment flag if end of path */

    if (!i) return FR_INVALID_NAME;		/* Reject null string */
    if (sfn[0] == 0xE5u) sfn[0] = 0x05u;	/* When first char collides with 0xE5, replace it with 0x05 */

    if (ni == 8u) b <<= 2u;
    if ((b & 0x03u) == 0x01u) c |= NS_EXT;	/* NT flag (Extension has only small capital) */
    if ((b & 0x0Cu) == 0x04u) c |= NS_BODY;	/* NT flag (Filename has only small capital) */

    sfn[NS] = c;		/* Store NT flag, File name is created */

    return FR_OK;
#endif
}




/*-----------------------------------------------------------------------*/
/* Get file information from directory entry                             */
/*-----------------------------------------------------------------------*/
#if _FS_MINIMIZE <= 1
static
void get_fileinfo (		/* No return code */
    DIR *dj,			/* Pointer to the directory object */
    FILINFO *fno	 	/* Pointer to the file information to be filled */
)
{
    int i;
    BYTE c, *dir;
    char *p;
#if _USE_LFN
    BYTE nt;
#endif /* C-STAT */

    p = fno->fname;
    if (dj->sect) {
        dir = dj->dir;
#if _USE_LFN
        nt = dir[DIR_NTres];		/* NT flag */
#endif /* C-STAT */
        for (i = 0; i < 8; i++) {	/* Copy name body */
            c = dir[i];
            if (c == ' ') break;
            if (c == 0x05) c = 0xE5;
#if _USE_LFN
            if (_USE_LFN && (nt & NS_BODY) && IsUpper(c)) c += 0x20;
#endif /* C-STAT */
            *p++ = c;
        }
        if (dir[8] != ' ') {		/* Copy name extension */
            *p++ = '.';
            for (i = 8; i < 11; i++) {
                c = dir[i];
                if (c == ' ') break;
#if _USE_LFN
                if (_USE_LFN && (nt & NS_EXT) && IsUpper(c)) c += 0x20;
#endif /* C-STAT */
                *p++ = c;
            }
        }
        fno->fattrib = dir[DIR_Attr];				/* Attribute */
        fno->fsize = LD_DWORD(dir+DIR_FileSize);	/* Size */
        fno->fdate = LD_WORD(dir+DIR_WrtDate);		/* Date */
        fno->ftime = LD_WORD(dir+DIR_WrtTime);		/* Time */
    }
    *p = 0;

#if _USE_LFN
    if (fno->lfname) {
        XCHAR *tp = fno->lfname;
        WCHAR w, *lfn;

        i = 0;
        if (dj->sect && dj->lfn_idx != 0xFFFF) {/* Get LFN if available */
            lfn = dj->lfn;
            while ((w = *lfn++) != 0) {			/* Get an LFN char */
#if !_LFN_UNICODE
                w = ff_convert(w, 0);			/* Unicode -> OEM conversion */
                if (!w) { i = 0; break; }		/* Could not convert, no LFN */
                if (_DF1S && w >= 0x100)		/* Put 1st byte if it is a DBC */
                    tp[i++] = (XCHAR)(w >> 8);
#endif
                if (i >= fno->lfsize - 1) { i = 0; break; }	/* Buffer overrun, no LFN */
                tp[i++] = (XCHAR)w;
            }
        }
        tp[i] = 0;	/* Terminator */
    }
#endif
}
#endif /* _FS_MINIMIZE <= 1 */




/*-----------------------------------------------------------------------*/
/* Follow a file path                                                    */
/*-----------------------------------------------------------------------*/

static
FRESULT follow_path (	/* FR_OK(0): successful, !=0: error code */
    DIR *dj,			/* Directory object to return last directory and found object */
    const XCHAR *path	/* Full-path string to find a file or directory */
)
{
    FRESULT res;
    BYTE *dir, last;

    while ((!_USE_LFN) && (*path == ' ')) path++;	/* Skip leading spaces */
#if _FS_RPATH
    if ((*path == '/') || (*path == '\\')) { /* There is a heading separator */
        path++;	dj->sclust = 0;		/* Strip it and start from the root dir */
    } else {							/* No heading separator */
        dj->sclust = dj->fs->cdir;	/* Start from the current dir */
    }
#else
    if ((*path == '/') || (*path == '\\'))	/* Strip heading separator if exist */
        path++;
    dj->sclust = 0;						/* Start from the root dir */
#endif

    if ((UINT)*path < ' ') {			/* Null path means the start directory itself */
        res = dir_seek(dj, 0);
        dj->dir = NULL;

    } else {							/* Follow path */
        for (;;) {
            res = create_name(dj, &path);	/* Get a segment */
            if (res != FR_OK) break;
            res = dir_find(dj);				/* Find it */
            last = *(dj->fn+NS) & NS_LAST;
            if (res != FR_OK) {				/* Could not find the object */
                if ((res == FR_NO_FILE) && (!last))
                    res = FR_NO_PATH;
                break;
            }
            if (last) break;				/* Last segment match. Function completed. */
            dir = dj->dir;					/* There is next segment. Follow the sub directory */
            if (!(dir[DIR_Attr] & AM_DIR)) { /* Cannot follow because it is a file */
                res = FR_NO_PATH; break;
            }
            dj->sclust = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
        }
    }

    return res;
}




/*-----------------------------------------------------------------------*/
/* Load boot record and check if it is an FAT boot record                */
/*-----------------------------------------------------------------------*/

static
BYTE check_fs (	/* 0:The FAT boot record, 1:Valid boot record but not an FAT, 2:Not a boot record, 3:Error */
    FATFS *fs,	/* File system object */
    DWORD sect	/* Sector# (lba) to check if it is an FAT boot record or not */
)
{
    if (disk_read(fs->drive, fs->win, sect, 1) != RES_OK)	/* Load boot record */
        return 3;
    if (LD_WORD(&fs->win[BS_55AA]) != 0xAA55)		/* Check record signature (always placed at offset 510 even if the sector size is >512) */
        return 2;

    if ((LD_DWORD(&fs->win[BS_FilSysType]) & 0xFFFFFF) == 0x544146)	/* Check "FAT" string */
        return 0;
    if ((LD_DWORD(&fs->win[BS_FilSysType32]) & 0xFFFFFF) == 0x544146)
        return 0;

    return 1;
}




/*-----------------------------------------------------------------------*/
/* Make sure that the file system is valid                               */
/*-----------------------------------------------------------------------*/


FRESULT chk_mounted (	/* FR_OK(0): successful, !=0: any error occurred */
    const XCHAR **path,	/* Pointer to pointer to the path name (drive number) */
    FATFS **rfs,		/* Pointer to pointer to the found file system object */
    BYTE chk_wp			/* !=0: Check media write protection for write access */
)
{
    BYTE fmt, *tbl;
    UINT vol;
    DSTATUS stat;
    DWORD bsect, fsize, tsect, mclst;
    const XCHAR *p = *path;
    FATFS *fs;

    /* Get logical drive number from the path name */
    vol = p[0] - '0';				/* Is there a drive number? */
    if ((vol <= 9) && (p[1] == ':')) {	/* Found a drive number, get and strip it */
        p += 2; *path = p;			/* Return pointer to the path name */
    } else {						/* No drive number is given */
#if _FS_RPATH
        vol = Drive;				/* Use current drive */
#else
        vol = 0;					/* Use drive 0 */
#endif
    }

    /* Check if the logical drive is valid or not */
    if (vol >= _DRIVES) 			/* Is the drive number valid? */
        return FR_INVALID_DRIVE;
    *rfs = fs = FatFs[vol];			/* Return pointer to the corresponding file system object */
    if (!fs) return FR_NOT_ENABLED;	/* Is the file system object available? */

    ENTER_FF(fs);					/* Lock file system */

    if (fs->fs_type) {				/* If the logical drive has been mounted */
        stat = disk_status(fs->drive);
        if (!(stat & STA_NOINIT)) {	/* and the physical drive is kept initialized (has not been changed), */
#if !_FS_READONLY
            if (chk_wp && (stat & STA_PROTECT))	/* Check write protection if needed */
                return FR_WRITE_PROTECTED;
#endif
            return FR_OK;			/* The file system object is valid */
        }
    }

    /* The logical drive must be mounted. Following code attempts to mount the volume */

    fs->fs_type = 0;					/* Clear the file system object */
    fs->drive = (BYTE)LD2PD(vol);		/* Bind the logical drive and a physical drive */
    stat = disk_initialize(fs->drive);	/* Initialize low level disk I/O layer */
    if (stat & STA_NOINIT)				/* Check if the drive is ready */
        return FR_NOT_READY;
#if _MAX_SS != 512						/* Get disk sector size if needed */
    if (disk_ioctl(fs->drive, GET_SECTOR_SIZE, &SS(fs)) != RES_OK || SS(fs) > _MAX_SS)
        return FR_NO_FILESYSTEM;
#endif
#if !_FS_READONLY
    if (chk_wp && (stat & STA_PROTECT))	/* Check disk write protection if needed */
        return FR_WRITE_PROTECTED;
#endif
    /* Search FAT partition on the drive */
    fmt = check_fs(fs, bsect = 0);		/* Check sector 0 as an SFD format */
    if (fmt == 1) {						/* Not an FAT boot record, it may be partitioned */
        /* Check a partition listed in top of the partition table */
        tbl = &fs->win[MBR_Table + LD2PT(vol) * 16];	/* Partition table */
        if (tbl[4]) {									/* Is the partition existing? */
            bsect = LD_DWORD(&tbl[8]);					/* Partition offset in LBA */
            fmt = check_fs(fs, bsect);					/* Check the partition */
        }
    }
    if (fmt == 3) return FR_DISK_ERR;
    if (fmt || (LD_WORD(fs->win+BPB_BytsPerSec) != SS(fs)))	/* No valid FAT partition is found */
        return FR_NO_FILESYSTEM;

    /* Initialize the file system object */
    fsize = LD_WORD(fs->win+BPB_FATSz16);				/* Number of sectors per FAT */
    if (!fsize) fsize = LD_DWORD(fs->win+BPB_FATSz32);
    fs->sects_fat = fsize;
    fs->n_fats = fs->win[BPB_NumFATs];					/* Number of FAT copies */
    fsize *= fs->n_fats;								/* (Number of sectors in FAT area) */
    fs->fatbase = bsect + LD_WORD(fs->win+BPB_RsvdSecCnt); /* FAT start sector (lba) */
    fs->csize = fs->win[BPB_SecPerClus];				/* Number of sectors per cluster */
    fs->n_rootdir = LD_WORD(fs->win+BPB_RootEntCnt);	/* Number of root directory entries */
    tsect = LD_WORD(fs->win+BPB_TotSec16);				/* Number of sectors on the volume */
    if (!tsect) tsect = LD_DWORD(fs->win+BPB_TotSec32);
    fs->max_clust = mclst = (tsect						/* Last cluster# + 1 (Number of clusters + 2) */
        - LD_WORD(fs->win+BPB_RsvdSecCnt) - fsize - fs->n_rootdir / (SS(fs)/32)
        ) / fs->csize + 2;

    fmt = FS_FAT12;										/* Determine the FAT sub type */
    if (mclst >= 0xFF7) fmt = FS_FAT16;					/* Number of clusters >= 0xFF5 */
    if (mclst >= 0xFFF7) fmt = FS_FAT32;				/* Number of clusters >= 0xFFF5 */

    if (fmt == FS_FAT32)
        fs->dirbase = LD_DWORD(fs->win+BPB_RootClus);	/* Root directory start cluster */
    else
        fs->dirbase = fs->fatbase + fsize;				/* Root directory start sector (lba) */
    fs->database = fs->fatbase + fsize + fs->n_rootdir / (SS(fs)/32);	/* Data start sector (lba) */

#if !_FS_READONLY
    /* Initialize allocation information */
    fs->free_clust = 0xFFFFFFFF;
    fs->wflag = 0;
    /* Get fsinfo if needed */
    if (fmt == FS_FAT32) {
         fs->fsi_flag = 0;
        fs->fsi_sector = bsect + LD_WORD(fs->win+BPB_FSInfo);
        if ((disk_read(fs->drive, fs->win, fs->fsi_sector, 1) == RES_OK) &&
            (LD_WORD(fs->win+BS_55AA) == 0xAA55) &&
            (LD_DWORD(fs->win+FSI_LeadSig) == 0x41615252) &&
            (LD_DWORD(fs->win+FSI_StrucSig) == 0x61417272)) {
            fs->last_clust = LD_DWORD(fs->win+FSI_Nxt_Free);
            fs->free_clust = LD_DWORD(fs->win+FSI_Free_Count);
        }
    }
#endif
    fs->fs_type = fmt;		/* FAT sub-type */
    fs->winsect = 0;		/* Invalidate sector cache */
#if _FS_RPATH
    fs->cdir = 0;			/* Current directory (root dir) */
#endif
    fs->id = ++Fsid;		/* File system mount ID */

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* Check if the file/dir object is valid or not                          */
/*-----------------------------------------------------------------------*/

static
FRESULT validate (	/* FR_OK(0): The object is valid, !=0: Invalid */
    FATFS *fs,		/* Pointer to the file system object */
    WORD id			/* Member id of the target object to be checked */
)
{
    if ((!fs) || (!fs->fs_type) || (fs->id != id))
        return FR_INVALID_OBJECT;

    ENTER_FF(fs);		/* Lock file system */

    if (disk_status(fs->drive) & STA_NOINIT)
        return FR_NOT_READY;

    return FR_OK;
}




/*--------------------------------------------------------------------------

   Public Functions

--------------------------------------------------------------------------*/



/*-----------------------------------------------------------------------*/
/* Mount/Unmount a Logical Drive                                         */
/*-----------------------------------------------------------------------*/

FRESULT f_mount (
    BYTE vol,		/* Logical drive number to be mounted/unmounted */
    FATFS *fs		/* Pointer to new file system object (NULL for unmount)*/
)
{
    FATFS *rfs;


    if (vol >= _DRIVES)				/* Check if the drive number is valid */
        return FR_INVALID_DRIVE;
    rfs = FatFs[vol];				/* Get current fs object */

    if (rfs) {
#if _FS_REENTRANT					/* Discard sync object of the current volume */
        if (!ff_del_syncobj(rfs->sobj)) return FR_INT_ERR;
#endif
        rfs->fs_type = 0;			/* Clear old fs object */
    }

    if (fs) {
        fs->fs_type = 0;			/* Clear new fs object */
#if _FS_REENTRANT					/* Create sync object for the new volume */
        if (!ff_cre_syncobj(vol, &fs->sobj)) return FR_INT_ERR;
#endif
    }
    FatFs[vol] = fs;				/* Register new fs object */

    return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* Open or Create a File                                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_open (
    FIL *fp,			/* Pointer to the blank file object */
    const XCHAR *path,	/* Pointer to the file name */
    BYTE mode			/* Access mode and file open mode flags */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    fp->fs = NULL;		/* Clear file object */
#if !_FS_READONLY
    mode &= (FA_READ | FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW);
    res = chk_mounted(&path, &dj.fs, (BYTE)(mode & (FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW)));
#else
    mode &= FA_READ;
    res = chk_mounted(&path, &dj.fs, 0);
#endif
    if (res != FR_OK) LEAVE_FF(dj.fs, res);
    INITBUF(dj, sfn, lfn);
    res = follow_path(&dj, path);	/* Follow the file path */

#if !_FS_READONLY
    /* Create or Open a file */
    if (mode & (FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW)) {
        DWORD ps, cl;

        if (res != FR_OK) {			/* No file, create new */
            if (res == FR_NO_FILE)	/* There is no file to open, create a new entry */
                res = dir_register(&dj);
            if (res != FR_OK) LEAVE_FF(dj.fs, res);
            mode |= FA_CREATE_ALWAYS;
            dir = dj.dir;			/* Created entry (SFN entry) */
        }
        else {						/* Any object is already existing */
            if (mode & FA_CREATE_NEW)			/* Cannot create new */
                LEAVE_FF(dj.fs, FR_EXIST);
            dir = dj.dir;
            if ((!dir) || (dir[DIR_Attr] & (AM_RDO | AM_DIR)))	/* Cannot overwrite it (R/O or DIR) */
                LEAVE_FF(dj.fs, FR_DENIED);
            if (mode & FA_CREATE_ALWAYS) {		/* Resize it to zero on over write mode */
                cl = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);	/* Get start cluster */
                ST_WORD(dir+DIR_FstClusHI, 0);	/* cluster = 0 */
                ST_WORD(dir+DIR_FstClusLO, 0);
                ST_DWORD(dir+DIR_FileSize, 0);	/* size = 0 */
                dj.fs->wflag = 1;
                ps = dj.fs->winsect;			/* Remove the cluster chain */
                if (cl) {
                    res = remove_chain(dj.fs, cl);
                    if (res) LEAVE_FF(dj.fs, res);
                    dj.fs->last_clust = cl - 1;	/* Reuse the cluster hole */
                }
                res = move_window(dj.fs, ps);
                if (res != FR_OK) LEAVE_FF(dj.fs, res);
            }
        }
        if (mode & FA_CREATE_ALWAYS) {
            dir[DIR_Attr] = 0;					/* Reset attribute */
            ps = get_fattime();
            ST_DWORD(dir+DIR_CrtTime, ps);		/* Created time */
            dj.fs->wflag = 1;
            mode |= FA__WRITTEN;				/* Set file changed flag */
        }
    }
    /* Open an existing file */
    else {
#endif /* !_FS_READONLY */
        if (res != FR_OK) LEAVE_FF(dj.fs, res);	/* Follow failed */
        dir = dj.dir;
        if ((!dir) || (dir[DIR_Attr] & AM_DIR))	/* It is a directory */
            LEAVE_FF(dj.fs, FR_NO_FILE);
#if !_FS_READONLY
        if ((mode & FA_WRITE) && (dir[DIR_Attr] & AM_RDO)) /* R/O violation */
            LEAVE_FF(dj.fs, FR_DENIED);
    }
    fp->dir_sect = dj.fs->winsect;		/* Pointer to the directory entry */
    fp->dir_ptr = dj.dir;
#endif
    fp->flag = mode;					/* File access mode */
    fp->org_clust =						/* File start cluster */
        ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
    fp->fsize = LD_DWORD(dir+DIR_FileSize);	/* File size */
    fp->fptr = 0; fp->csect = 255;		/* File pointer */
    fp->dsect = 0;
    fp->fs = dj.fs; fp->id = dj.fs->id;	/* Owner file system object of the file */

    LEAVE_FF(dj.fs, FR_OK);
}




/*-----------------------------------------------------------------------*/
/* Read File                                                             */
/*-----------------------------------------------------------------------*/

FRESULT f_read (
    FIL *fp, 		/* Pointer to the file object */
    void *buff,		/* Pointer to data buffer */
    UINT btr,		/* Number of bytes to read */
    UINT *br		/* Pointer to number of bytes read */
)
{
    FRESULT res;
    DWORD clst, sect, remain;
    UINT rcnt, cc;
    BYTE *rbuff = buff;


    *br = 0;	/* Initialize bytes read */

    res = validate(fp->fs, fp->id);					/* Check validity of the object */
    if (res != FR_OK) LEAVE_FF(fp->fs, res);
    if (fp->flag & FA__ERROR)						/* Check abort flag */
        LEAVE_FF(fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_READ)) 						/* Check access mode */
        LEAVE_FF(fp->fs, FR_DENIED);
    remain = fp->fsize - fp->fptr;
    if (btr > remain) btr = (UINT)remain;			/* Truncate btr by remaining bytes */

    for ( ;  btr;									/* Repeat until all data transferred */
        rbuff += rcnt, fp->fptr += rcnt, *br += rcnt, btr -= rcnt) {
        if ((fp->fptr % SS(fp->fs)) == 0) {			/* On the sector boundary? */
            if (fp->csect >= fp->fs->csize) {		/* On the cluster boundary? */
                clst = (fp->fptr == 0) ?			/* On the top of the file? */
                    fp->org_clust : get_fat(fp->fs, fp->curr_clust);
                if (clst <= 1) ABORT(fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
                fp->curr_clust = clst;				/* Update current cluster */
                fp->csect = 0;						/* Reset sector offset in the cluster */
            }
            sect = clust2sect(fp->fs, fp->curr_clust);	/* Get current sector */
            if (!sect) ABORT(fp->fs, FR_INT_ERR);
            sect += fp->csect;
            cc = btr / SS(fp->fs);					/* When remaining bytes >= sector size, */
            if (cc) {								/* Read maximum contiguous sectors directly */
                if (fp->csect + cc > fp->fs->csize)	/* Clip at cluster boundary */
                    cc = fp->fs->csize - fp->csect;
                if (disk_read(fp->fs->drive, rbuff, sect, (BYTE)cc) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
#if !_FS_READONLY && _FS_MINIMIZE <= 2
#if _FS_TINY
                if (fp->fs->wflag && fp->fs->winsect - sect < cc)		/* Replace one of the read sectors with cached data if it contains a dirty sector */
                    mem_cpy(rbuff + ((fp->fs->winsect - sect) * SS(fp->fs)), fp->fs->win, SS(fp->fs));
#else
                if ((fp->flag & FA__DIRTY) && ((fp->dsect - sect) < cc))	/* Replace one of the read sectors with cached data if it contains a dirty sector */
                    mem_cpy(rbuff + ((fp->dsect - sect) * SS(fp->fs)), fp->buf, SS(fp->fs));
#endif
#endif
                fp->csect += (BYTE)cc;				/* Next sector address in the cluster */
                rcnt = SS(fp->fs) * cc;				/* Number of bytes transferred */
                continue;
            }
#if !_FS_TINY
#if !_FS_READONLY
            if (fp->flag & FA__DIRTY) {			/* Write sector I/O buffer if needed */
                if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
                fp->flag &= ~FA__DIRTY;
            }
#endif
            if (fp->dsect != sect) {			/* Fill sector buffer with file data */
                if (disk_read(fp->fs->drive, fp->buf, sect, 1) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
            }
#endif
            fp->dsect = sect;
            fp->csect++;							/* Next sector address in the cluster */
        }
        rcnt = SS(fp->fs) - (fp->fptr % SS(fp->fs));	/* Get partial sector data from sector buffer */
        if (rcnt > btr) rcnt = btr;
#if _FS_TINY
        if (move_window(fp->fs, fp->dsect))			/* Move sector window */
            ABORT(fp->fs, FR_DISK_ERR);
        mem_cpy(rbuff, &fp->fs->win[fp->fptr % SS(fp->fs)], rcnt);	/* Pick partial sector */
#else
        mem_cpy(rbuff, &fp->buf[fp->fptr % SS(fp->fs)], rcnt);	/* Pick partial sector */
#endif
    }

    LEAVE_FF(fp->fs, FR_OK);
}




#if !_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Write File                                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_write (
    FIL *fp,			/* Pointer to the file object */
    const void *buff,	/* Pointer to the data to be written */
    UINT btw,			/* Number of bytes to write */
    UINT *bw			/* Pointer to number of bytes written */
)
{
    FRESULT res;
    DWORD clst, sect;
    UINT wcnt, cc;
    const BYTE *wbuff = buff;


    *bw = 0;	/* Initialize bytes written */

    res = validate(fp->fs, fp->id);					/* Check validity of the object */
    if (res != FR_OK) LEAVE_FF(fp->fs, res);
    if (fp->flag & FA__ERROR)						/* Check abort flag */
        LEAVE_FF(fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_WRITE))						/* Check access mode */
        LEAVE_FF(fp->fs, FR_DENIED);
    if (fp->fsize + btw < fp->fsize) btw = 0;		/* File size cannot reach 4GB */

    for ( ;  btw;									/* Repeat until all data transferred */
        wbuff += wcnt, fp->fptr += wcnt, *bw += wcnt, btw -= wcnt) {
        if ((fp->fptr % SS(fp->fs)) == 0) {			/* On the sector boundary? */
            if (fp->csect >= fp->fs->csize) {		/* On the cluster boundary? */
                if (fp->fptr == 0) {				/* On the top of the file? */
                    clst = fp->org_clust;			/* Follow from the origin */
                    if (clst == 0)					/* When there is no cluster chain, */
                        fp->org_clust = clst = create_chain(fp->fs, 0);	/* Create a new cluster chain */
                } else {							/* Middle or end of the file */
                    clst = create_chain(fp->fs, fp->curr_clust);			/* Follow or stretch cluster chain */
                }
                if (clst == 0) break;				/* Could not allocate a new cluster (disk full) */
                if (clst == 1) ABORT(fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
                fp->curr_clust = clst;				/* Update current cluster */
                fp->csect = 0;						/* Reset sector address in the cluster */
            }
#if _FS_TINY
            if (fp->fs->winsect == fp->dsect && move_window(fp->fs, 0))	/* Write back data buffer prior to following direct transfer */
                ABORT(fp->fs, FR_DISK_ERR);
#else
            if (fp->flag & FA__DIRTY) {		/* Write back data buffer prior to following direct transfer */
                if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
                fp->flag &= ~FA__DIRTY;
            }
#endif
            sect = clust2sect(fp->fs, fp->curr_clust);	/* Get current sector */
            if (!sect) ABORT(fp->fs, FR_INT_ERR);
            sect += fp->csect;
            cc = btw / SS(fp->fs);					/* When remaining bytes >= sector size, */
            if (cc) {								/* Write maximum contiguous sectors directly */
                if (fp->csect + cc > fp->fs->csize)	/* Clip at cluster boundary */
                    cc = fp->fs->csize - fp->csect;
                if (disk_write(fp->fs->drive, wbuff, sect, (BYTE)cc) != RES_OK)
                    ABORT(fp->fs, FR_DISK_ERR);
#if _FS_TINY
                if (fp->fs->winsect - sect < cc) {	/* Refill sector cache if it gets dirty by the direct write */
                    mem_cpy(fp->fs->win, wbuff + ((fp->fs->winsect - sect) * SS(fp->fs)), SS(fp->fs));
                    fp->fs->wflag = 0;
                }
#else
                if (fp->dsect - sect < cc) {		/* Refill sector cache if it gets dirty by the direct write */
                    mem_cpy(fp->buf, wbuff + ((fp->dsect - sect) * SS(fp->fs)), SS(fp->fs));
                    fp->flag &= ~FA__DIRTY;
                }
#endif
                fp->csect += (BYTE)cc;				/* Next sector address in the cluster */
                wcnt = SS(fp->fs) * cc;				/* Number of bytes transferred */
                continue;
            }
#if _FS_TINY
            if (fp->fptr >= fp->fsize) {			/* Avoid silly buffer filling at growing edge */
                if (move_window(fp->fs, 0)) ABORT(fp->fs, FR_DISK_ERR);
                fp->fs->winsect = sect;
            }
#else
            if (fp->dsect != sect) {				/* Fill sector buffer with file data */
                            if(fp->fptr < fp->fsize)
                            {
                if (disk_read(fp->fs->drive, fp->buf, sect, 1) != RES_OK)
                                {
                        ABORT(fp->fs, FR_DISK_ERR);
                                }
                            }
            }
#endif
            fp->dsect = sect;
            fp->csect++;							/* Next sector address in the cluster */
        }
        wcnt = SS(fp->fs) - (fp->fptr % SS(fp->fs));	/* Put partial sector into file I/O buffer */
        if (wcnt > btw) wcnt = btw;
#if _FS_TINY
        if (move_window(fp->fs, fp->dsect))			/* Move sector window */
            ABORT(fp->fs, FR_DISK_ERR);
        mem_cpy(&fp->fs->win[fp->fptr % SS(fp->fs)], wbuff, wcnt);	/* Fit partial sector */
        fp->fs->wflag = 1;
#else
        mem_cpy(&fp->buf[fp->fptr % SS(fp->fs)], wbuff, wcnt);	/* Fit partial sector */
        fp->flag |= FA__DIRTY;
#endif
    }

    if (fp->fptr > fp->fsize) fp->fsize = fp->fptr;	/* Update file size if needed */
    fp->flag |= FA__WRITTEN;						/* Set file changed flag */

    LEAVE_FF(fp->fs, FR_OK);
}




/*-----------------------------------------------------------------------*/
/* Synchronize the File Object                                           */
/*-----------------------------------------------------------------------*/

FRESULT f_sync (
    FIL *fp		/* Pointer to the file object */
)
{
    FRESULT res;
    DWORD tim;
    BYTE *dir;


    res = validate(fp->fs, fp->id);		/* Check validity of the object */
    if (res == FR_OK) {
        if (fp->flag & FA__WRITTEN) {	/* Has the file been written? */
#if !_FS_TINY	/* Write-back dirty buffer */
            if (fp->flag & FA__DIRTY) {
                if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    LEAVE_FF(fp->fs, FR_DISK_ERR);
                fp->flag &= ~FA__DIRTY;
            }
#endif
            /* Update the directory entry */
            res = move_window(fp->fs, fp->dir_sect);
            if (res == FR_OK) {
                dir = fp->dir_ptr;
                dir[DIR_Attr] |= AM_ARC;					/* Set archive bit */
                ST_DWORD(dir+DIR_FileSize, fp->fsize);		/* Update file size */
                ST_WORD(dir+DIR_FstClusLO, fp->org_clust);	/* Update start cluster */
                ST_WORD(dir+DIR_FstClusHI, fp->org_clust >> 16);
                tim = get_fattime();			/* Updated time */
                ST_DWORD(dir+DIR_WrtTime, tim);
                fp->flag &= ~FA__WRITTEN;
                fp->fs->wflag = 1;
                res = sync(fp->fs);
            }
        }
    }

    LEAVE_FF(fp->fs, res);
}

#endif /* !_FS_READONLY */




/*-----------------------------------------------------------------------*/
/* Close File                                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_close (
    FIL *fp		/* Pointer to the file object to be closed */
)
{
    FRESULT res;


#if _FS_READONLY
    res = validate(fp->fs, fp->id);
    if (res == FR_OK) fp->fs = NULL;
    LEAVE_FF(fp->fs, res);
#else
    res = f_sync(fp);
    if (res == FR_OK) fp->fs = NULL;
    return res;
#endif
}




/*-----------------------------------------------------------------------*/
/* Change Current Drive/Directory                                        */
/*-----------------------------------------------------------------------*/

#if _FS_RPATH

FRESULT f_chdrive (
    BYTE drv		/* Drive number */
)
{
    if (drv >= _DRIVES) return FR_INVALID_DRIVE;

    Drive = drv;

    return FR_OK;
}




FRESULT f_chdir (
    const XCHAR *path	/* Pointer to the directory path */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    res = chk_mounted(&path, &dj.fs, 0);
    if (res == FR_OK) {
        INITBUF(dj, sfn, lfn);
        res = follow_path(&dj, path);		/* Follow the file path */
        if (res == FR_OK) {					/* Follow completed */
            dir = dj.dir;					/* Pointer to the entry */
            if (!dir) {
                dj.fs->cdir = 0;			/* No entry (root dir) */
            } else {
                if (dir[DIR_Attr] & AM_DIR)	/* Reached to the dir */
                    dj.fs->cdir = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
                else
                    res = FR_NO_PATH;		/* Could not reach the dir (it is a file) */
            }
        }
        if (res == FR_NO_FILE) res = FR_NO_PATH;
    }

    LEAVE_FF(dj.fs, res);
}

#endif



#if _FS_MINIMIZE <= 2
/*-----------------------------------------------------------------------*/
/* Seek File R/W Pointer                                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_lseek (
    FIL *fp,		/* Pointer to the file object */
    DWORD ofs		/* File pointer from top of file */
)
{
    FRESULT res;
    DWORD clst, bcs, nsect, ifptr;


    res = validate(fp->fs, fp->id);		/* Check validity of the object */
    if (res != FR_OK) LEAVE_FF(fp->fs, res);
    if (fp->flag & FA__ERROR)			/* Check abort flag */
        LEAVE_FF(fp->fs, FR_INT_ERR);
    if ((ofs > fp->fsize)					/* In read-only mode, clip offset with the file size */
#if !_FS_READONLY
         && (!(fp->flag & FA_WRITE))
#endif
        ) ofs = fp->fsize;

    ifptr = fp->fptr;
    fp->fptr = nsect = 0; fp->csect = 255;
    if (ofs > 0) {
        bcs = (DWORD)fp->fs->csize * SS(fp->fs);	/* Cluster size (byte) */
                if (0 == bcs)
                  res = FR_TIMEOUT;     /* C-STAT */
        if ((ifptr > 0) &&
            (((ofs - 1) / bcs) >= ((ifptr - 1) / bcs))) {	/* When seek to same or following cluster, */
            fp->fptr = (ifptr - 1) & ~(bcs - 1);	/* start from the current cluster */
            ofs -= fp->fptr;
            clst = fp->curr_clust;
        } else {									/* When seek to back cluster, */
            clst = fp->org_clust;					/* start from the first cluster */
#if !_FS_READONLY
            if (clst == 0) {						/* If no cluster chain, create a new chain */
                clst = create_chain(fp->fs, 0);
                if (clst == 1) ABORT(fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
                fp->org_clust = clst;
            }
#endif
            fp->curr_clust = clst;
        }
        if (clst != 0) {
            while (ofs > bcs) {						/* Cluster following loop */
#if !_FS_READONLY
                if (fp->flag & FA_WRITE) {			/* Check if in write mode or not */
                    clst = create_chain(fp->fs, clst);	/* Force stretch if in write mode */
                    if (clst == 0) {				/* When disk gets full, clip file size */
                        ofs = bcs; break;
                    }
                } else
#endif
                    clst = get_fat(fp->fs, clst);	/* Follow cluster chain if not in write mode */
                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
                if ((clst <= 1) || (clst >= fp->fs->max_clust)) ABORT(fp->fs, FR_INT_ERR);
                fp->curr_clust = clst;
                fp->fptr += bcs;
                ofs -= bcs;
            }
            fp->fptr += ofs;
            fp->csect = (BYTE)(ofs / SS(fp->fs));	/* Sector offset in the cluster */
            if (ofs % SS(fp->fs)) {
                nsect = clust2sect(fp->fs, clst);	/* Current sector */
                if (!nsect) ABORT(fp->fs, FR_INT_ERR);
                nsect += fp->csect;
                fp->csect++;
            }
        }
    }
    if ((fp->fptr % SS(fp->fs)) && (nsect != fp->dsect)) {
#if !_FS_TINY
#if !_FS_READONLY
        if (fp->flag & FA__DIRTY) {			/* Write-back dirty buffer if needed */
            if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                ABORT(fp->fs, FR_DISK_ERR);
            fp->flag &= ~FA__DIRTY;
        }
#endif
        if (disk_read(fp->fs->drive, fp->buf, nsect, 1) != RES_OK)
            ABORT(fp->fs, FR_DISK_ERR);
#endif
        fp->dsect = nsect;
    }
#if !_FS_READONLY
    if (fp->fptr > fp->fsize) {			/* Set changed flag if the file size is extended */
        fp->fsize = fp->fptr;
        fp->flag |= FA__WRITTEN;
    }
#endif

    LEAVE_FF(fp->fs, res);
}




#if _FS_MINIMIZE <= 1
/*-----------------------------------------------------------------------*/
/* Create a Directroy Object                                             */
/*-----------------------------------------------------------------------*/

FRESULT f_opendir (
    DIR *dj,			/* Pointer to directory object to create */
    const XCHAR *path	/* Pointer to the directory path */
)
{
    FRESULT res;
    NAMEBUF(sfn, lfn);
    BYTE *dir;

    res = chk_mounted(&path, &dj->fs, 0);
    if (res == FR_OK) {
        INITBUF((*dj), sfn, lfn);
        res = follow_path(dj, path);			/* Follow the path to the directory */
        if (res == FR_OK) {						/* Follow completed */
            dir = dj->dir;
            if (dir) {							/* It is not the root dir */
                if (dir[DIR_Attr] & AM_DIR) {	/* The object is a directory */
                    dj->sclust = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
                } else {						/* The object is not a directory */
                    res = FR_NO_PATH;
                }
            }
            if (res == FR_OK) {
                dj->id = dj->fs->id;
                res = dir_seek(dj, 0);			/* Rewind dir */
            }
        }
        if (res == FR_NO_FILE) res = FR_NO_PATH;
    }

    LEAVE_FF(dj->fs, res);
}




/*-----------------------------------------------------------------------*/
/* Read Directory Entry in Sequense                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_readdir (
    DIR *dj,			/* Pointer to the open directory object */
    FILINFO *fno		/* Pointer to file information to return */
)
{
    FRESULT res;
    NAMEBUF(sfn, lfn);


    res = validate(dj->fs, dj->id);			/* Check validity of the object */
    if (res == FR_OK) {
        INITBUF((*dj), sfn, lfn);
        if (!fno) {
            res = dir_seek(dj, 0);
        } else {
            res = dir_read(dj);
            if (res == FR_NO_FILE) {
                dj->sect = 0;
                res = FR_OK;
            }
            if (res == FR_OK) {				/* A valid entry is found */
                get_fileinfo(dj, fno);		/* Get the object information */
                res = dir_next(dj, FALSE);	/* Increment index for next */
                if (res == FR_NO_FILE) {
                    dj->sect = 0;
                    res = FR_OK;
                }
            }
        }
    }

    LEAVE_FF(dj->fs, res);
}



#if _FS_MINIMIZE == 0
/*-----------------------------------------------------------------------*/
/* Get File Status                                                       */
/*-----------------------------------------------------------------------*/

FRESULT f_stat (
    const XCHAR *path,	/* Pointer to the file path */
    FILINFO *fno		/* Pointer to file information to return */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);


    res = chk_mounted(&path, &dj.fs, 0);
    if (res == FR_OK) {
        INITBUF(dj, sfn, lfn);
        res = follow_path(&dj, path);	/* Follow the file path */
        if (res == FR_OK) {				/* Follow completed */
            if (dj.dir)	/* Found an object */
                get_fileinfo(&dj, fno);
            else		/* It is root dir */
                res = FR_INVALID_NAME;
        }
    }

    LEAVE_FF(dj.fs, res);
}



#if !_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Get Number of Free Clusters                                           */
/*-----------------------------------------------------------------------*/

FRESULT f_getfree (
    const XCHAR *path,	/* Pointer to the logical drive number (root dir) */
    DWORD *nclst,		/* Pointer to the variable to return number of free clusters */
    FATFS **fatfs		/* Pointer to pointer to corresponding file system object to return */
)
{
    FRESULT res;
    DWORD n, clst, sect, stat;
    UINT i;
    BYTE fat, *p;


    /* Get drive number */
    res = chk_mounted(&path, fatfs, 0);
    if (res != FR_OK) LEAVE_FF(*fatfs, res);

    /* If number of free cluster is valid, return it without cluster scan. */
    if ((*fatfs)->free_clust <= (*fatfs)->max_clust - 2) {
        *nclst = (*fatfs)->free_clust;
        LEAVE_FF(*fatfs, FR_OK);
    }

    /* Get number of free clusters */
    fat = (*fatfs)->fs_type;
    n = 0;
    if (fat == FS_FAT12) {
        clst = 2;
        do {
            stat = get_fat(*fatfs, clst);
            if (stat == 0xFFFFFFFF) LEAVE_FF(*fatfs, FR_DISK_ERR);
            if (stat == 1) LEAVE_FF(*fatfs, FR_INT_ERR);
            if (stat == 0) n++;
        } while (++clst < (*fatfs)->max_clust);
    } else {
        clst = (*fatfs)->max_clust;
        sect = (*fatfs)->fatbase;
        i = 0; p = 0;
        do {
            if (!i) {
                res = move_window(*fatfs, sect++);
                if (res != FR_OK)
                    LEAVE_FF(*fatfs, res);
                p = (*fatfs)->win;
                i = SS(*fatfs);
            }
            if (fat == FS_FAT16) {
                if (LD_WORD(p) == 0) n++;
                p += 2; i -= 2;
            } else {
                if ((LD_DWORD(p) & 0x0FFFFFFF) == 0) n++;
                p += 4; i -= 4;
            }
        } while (--clst);
    }
    (*fatfs)->free_clust = n;
    if (fat == FS_FAT32) (*fatfs)->fsi_flag = 1;
    *nclst = n;

    LEAVE_FF(*fatfs, FR_OK);
}




/*-----------------------------------------------------------------------*/
/* Truncate File                                                         */
/*-----------------------------------------------------------------------*/

FRESULT f_truncate (
    FIL *fp		/* Pointer to the file object */
)
{
    FRESULT res;
    DWORD ncl;


    res = validate(fp->fs, fp->id);		/* Check validity of the object */
    if (res != FR_OK) LEAVE_FF(fp->fs, res);
    if (fp->flag & FA__ERROR)			/* Check abort flag */
        LEAVE_FF(fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_WRITE))			/* Check access mode */
        LEAVE_FF(fp->fs, FR_DENIED);

    if (fp->fsize > fp->fptr) {
        fp->fsize = fp->fptr;	/* Set file size to current R/W point */
        fp->flag |= FA__WRITTEN;
        if (fp->fptr == 0) {	/* When set file size to zero, remove entire cluster chain */
            res = remove_chain(fp->fs, fp->org_clust);
            fp->org_clust = 0;
        } else {				/* When truncate a part of the file, remove remaining clusters */
            ncl = get_fat(fp->fs, fp->curr_clust);
            res = FR_OK;
            if (ncl == 0xFFFFFFFF) res = FR_DISK_ERR;
            if (ncl == 1) res = FR_INT_ERR;
            if ((res == FR_OK) && (ncl < fp->fs->max_clust)) {
                res = put_fat(fp->fs, fp->curr_clust, 0x0FFFFFFF);
                if (res == FR_OK) res = remove_chain(fp->fs, ncl);
            }
        }
    }
    if (res != FR_OK) fp->flag |= FA__ERROR;

    LEAVE_FF(fp->fs, res);
}




/*-----------------------------------------------------------------------*/
/* Delete a File or Directory                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_unlink (
    const XCHAR *path		/* Pointer to the file or directory path */
)
{
    FRESULT res;
    DIR dj, sdj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;
    DWORD dclst;


    res = chk_mounted(&path, &dj.fs, 1);
    if (res != FR_OK) LEAVE_FF(dj.fs, res);

    INITBUF(dj, sfn, lfn);
    res = follow_path(&dj, path);			/* Follow the file path */
#if _FS_RPATH
        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
        res = FR_INVALID_NAME;
#endif /* C-STAT */
        if (res != FR_OK) LEAVE_FF(dj.fs, res); /* Follow failed */

    dir = dj.dir;
    if (!dir)								/* Is it the root directory? */
        LEAVE_FF(dj.fs, FR_INVALID_NAME);
    if (dir[DIR_Attr] & AM_RDO)				/* Is it a R/O object? */
        LEAVE_FF(dj.fs, FR_DENIED);
    dclst = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);

    if (dir[DIR_Attr] & AM_DIR) {			/* It is a sub-directory */
        if (dclst < 2) LEAVE_FF(dj.fs, FR_INT_ERR);
        mem_cpy(&sdj, &dj, sizeof(DIR));	/* Check if the sub-dir is empty or not */
        sdj.sclust = dclst;
        res = dir_seek(&sdj, 2);
        if (res != FR_OK) LEAVE_FF(dj.fs, res);
        res = dir_read(&sdj);
        if (res == FR_OK) res = FR_DENIED;	/* Not empty sub-dir */
        if (res != FR_NO_FILE) LEAVE_FF(dj.fs, res);
    }

    res = dir_remove(&dj);					/* Remove directory entry */
    if (res == FR_OK) {
        if (dclst)
            res = remove_chain(dj.fs, dclst);	/* Remove the cluster chain */
        if (res == FR_OK) res = sync(dj.fs);
    }

    LEAVE_FF(dj.fs, res);
}




/*-----------------------------------------------------------------------*/
/* Create a Directory                                                    */
/*-----------------------------------------------------------------------*/

FRESULT f_mkdir (
    const XCHAR *path		/* Pointer to the directory path */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir, n;
    DWORD dsect, dclst, pclst, tim;


    res = chk_mounted(&path, &dj.fs, 1);
    if (res != FR_OK) LEAVE_FF(dj.fs, res);

    INITBUF(dj, sfn, lfn);
    res = follow_path(&dj, path);			/* Follow the file path */
    if (res == FR_OK) res = FR_EXIST;		/* Any file or directory is already existing */
#if _FS_RPATH
        if (_FS_RPATH && res == FR_NO_FILE && (dj.fn[NS] & NS_DOT))
        res = FR_INVALID_NAME;
#endif /* C-STAT */
    if (res != FR_NO_FILE)					/* Any error occurred */
        LEAVE_FF(dj.fs, res);

    dclst = create_chain(dj.fs, 0);			/* Allocate a new cluster for new directory table */
    res = FR_OK;
    if (dclst == 0) res = FR_DENIED;
    if (dclst == 1) res = FR_INT_ERR;
    if (dclst == 0xFFFFFFFF) res = FR_DISK_ERR;
    if (res == FR_OK)
        res = move_window(dj.fs, 0);
    if (res != FR_OK) LEAVE_FF(dj.fs, res);
    dsect = clust2sect(dj.fs, dclst);

    dir = dj.fs->win;						/* Initialize the new directory table */
    mem_set(dir, 0, SS(dj.fs));
    mem_set(dir+DIR_Name, ' ', 8+3);		/* Create "." entry */
    dir[DIR_Name] = '.';
    dir[DIR_Attr] = AM_DIR;
    tim = get_fattime();
    ST_DWORD(dir+DIR_WrtTime, tim);
    ST_WORD(dir+DIR_FstClusLO, dclst);
    ST_WORD(dir+DIR_FstClusHI, dclst >> 16);
    mem_cpy(dir+32, dir, 32); 			/* Create ".." entry */
    dir[33] = '.';
    pclst = dj.sclust;
    if ((dj.fs->fs_type == FS_FAT32) && (pclst == dj.fs->dirbase))
        pclst = 0;
    ST_WORD(dir+32+DIR_FstClusLO, pclst);
    ST_WORD(dir+32+DIR_FstClusHI, pclst >> 16);
    for (n = 0; n < dj.fs->csize; n++) {	/* Write dot entries and clear left sectors */
        dj.fs->winsect = dsect++;
        dj.fs->wflag = 1;
        res = move_window(dj.fs, 0);
        if (res) LEAVE_FF(dj.fs, res);
        mem_set(dir, 0, SS(dj.fs));
    }

    res = dir_register(&dj);
    if (res != FR_OK) {
        remove_chain(dj.fs, dclst);
    } else {
        dir = dj.dir;
        dir[DIR_Attr] = AM_DIR;					/* Attribute */
        ST_DWORD(dir+DIR_WrtTime, tim);			/* Create time */
        ST_WORD(dir+DIR_FstClusLO, dclst);		/* Table start cluster */
        ST_WORD(dir+DIR_FstClusHI, dclst >> 16);
        dj.fs->wflag = 1;
        res = sync(dj.fs);
    }

    LEAVE_FF(dj.fs, res);
}




/*-----------------------------------------------------------------------*/
/* Change File Attribute                                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_chmod (
    const XCHAR *path,	/* Pointer to the file path */
    BYTE value,			/* Attribute bits */
    BYTE mask			/* Attribute mask to change */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    res = chk_mounted(&path, &dj.fs, 1);
    if (res == FR_OK) {
        INITBUF(dj, sfn, lfn);
        res = follow_path(&dj, path);		/* Follow the file path */
#if _FS_RPATH
        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
            res = FR_INVALID_NAME;
#endif /* C-STAT */
                if (res == FR_OK) {
            dir = dj.dir;
            if (!dir) {						/* Is it a root directory? */
                res = FR_INVALID_NAME;
            } else {						/* File or sub directory */
                mask &= AM_RDO|AM_HID|AM_SYS|AM_ARC;	/* Valid attribute mask */
                dir[DIR_Attr] = (value & mask) | (dir[DIR_Attr] & (BYTE)~mask);	/* Apply attribute change */
                dj.fs->wflag = 1;
                res = sync(dj.fs);
            }
        }
    }

    LEAVE_FF(dj.fs, res);
}




/*-----------------------------------------------------------------------*/
/* Change Timestamp                                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_utime (
    const XCHAR *path,	/* Pointer to the file/directory name */
    const FILINFO *fno	/* Pointer to the time-stamp to be set */
)
{
    FRESULT res;
    DIR dj;
    NAMEBUF(sfn, lfn);
    BYTE *dir;


    res = chk_mounted(&path, &dj.fs, 1);
    if (res == FR_OK) {
        INITBUF(dj, sfn, lfn);
        res = follow_path(&dj, path);	/* Follow the file path */
#if _FS_RPATH
        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
            res = FR_INVALID_NAME;
#endif  /* C-STAT */
        if (res == FR_OK) {
            dir = dj.dir;
            if (!dir) {				/* Root directory */
                res = FR_INVALID_NAME;
            } else {				/* File or sub-directory */
                ST_WORD(dir+DIR_WrtTime, fno->ftime);
                ST_WORD(dir+DIR_WrtDate, fno->fdate);
                dj.fs->wflag = 1;
                res = sync(dj.fs);
            }
        }
    }

    LEAVE_FF(dj.fs, res);
}

/*-----------------------------------------------------------------------*/
/* Rename File/Directory                                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_rename (
    const XCHAR *path_old,	/* Pointer to the old name */
    const XCHAR *path_new	/* Pointer to the new name */
)
{
    FRESULT res;
    DIR dj_old, dj_new;
    NAMEBUF(sfn, lfn);
    BYTE buf[21], *dir;
    DWORD dw;


    INITBUF(dj_old, sfn, lfn);
    res = chk_mounted(&path_old, &dj_old.fs, 1);
    if (res == FR_OK) {
        dj_new.fs = dj_old.fs;

        res = follow_path(&dj_old, path_old);	/* Check old object */
#if _FS_RPATH
                if (_FS_RPATH && (res == FR_OK) && (dj_old.fn[NS] & NS_DOT))
                    res = FR_INVALID_NAME;
#endif  /* C-STAT */
    }
    if (res != FR_OK) LEAVE_FF(dj_old.fs, res);	/* The old object is not found */

    if (!dj_old.dir) LEAVE_FF(dj_old.fs, FR_NO_FILE);	/* Is root dir? */
    mem_cpy(buf, dj_old.dir+DIR_Attr, 21);		/* Save the object information */

    mem_cpy(&dj_new, &dj_old, sizeof(DIR));
    res = follow_path(&dj_new, path_new);		/* Check new object */
    if (res == FR_OK) res = FR_EXIST;			/* The new object name is already existing */
    if (res == FR_NO_FILE) { 					/* Is it a valid path and no name collision? */
        res = dir_register(&dj_new);			/* Register the new object */
        if (res == FR_OK) {
            dir = dj_new.dir;					/* Copy object information into new entry */
            mem_cpy(dir+13, buf+2, 19);
            dir[DIR_Attr] = buf[0] | AM_ARC;
            dj_old.fs->wflag = 1;
            if (dir[DIR_Attr] & AM_DIR) {		/* Update .. entry in the directory if needed */
                dw = clust2sect(dj_new.fs, (DWORD)LD_WORD(dir+DIR_FstClusHI) | LD_WORD(dir+DIR_FstClusLO));
                if (!dw) {
                    res = FR_INT_ERR;
                } else {
                    res = move_window(dj_new.fs, dw);
                    dir = dj_new.fs->win+32;
                    if ((res == FR_OK) && (dir[1] == '.')) {
                        dw = ((dj_new.fs->fs_type == FS_FAT32) && (dj_new.sclust == dj_new.fs->dirbase)) ? 0 : dj_new.sclust;
                        ST_WORD(dir+DIR_FstClusLO, dw);
                        ST_WORD(dir+DIR_FstClusHI, dw >> 16);
                        dj_new.fs->wflag = 1;
                    }
                }
            }
            if (res == FR_OK) {
                res = dir_remove(&dj_old);			/* Remove old entry */
                if (res == FR_OK)
                    res = sync(dj_old.fs);
            }
        }
    }

    LEAVE_FF(dj_old.fs, res);
}

#endif /* !_FS_READONLY */
#endif /* _FS_MINIMIZE == 0 */
#endif /* _FS_MINIMIZE <= 1 */
#endif /* _FS_MINIMIZE <= 2 */



/*-----------------------------------------------------------------------*/
/* Forward data to the stream directly (Available on only _FS_TINY cfg)  */
/*-----------------------------------------------------------------------*/
#if _USE_FORWARD && _FS_TINY

FRESULT f_forward (
    FIL *fp, 						/* Pointer to the file object */
    UINT (*func)(const BYTE*,UINT),	/* Pointer to the streaming function */
    UINT btr,						/* Number of bytes to forward */
    UINT *bf						/* Pointer to number of bytes forwarded */
)
{
    FRESULT res;
    DWORD remain, clst, sect;
    UINT rcnt;


    *bf = 0;

    res = validate(fp->fs, fp->id);					/* Check validity of the object */
    if (res != FR_OK) LEAVE_FF(fp->fs, res);
    if (fp->flag & FA__ERROR)						/* Check error flag */
        LEAVE_FF(fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_READ))						/* Check access mode */
        LEAVE_FF(fp->fs, FR_DENIED);

    remain = fp->fsize - fp->fptr;
    if (btr > remain) btr = (UINT)remain;			/* Truncate btr by remaining bytes */

    for ( ;  btr && (*func)(NULL, 0);				/* Repeat until all data transferred or stream becomes busy */
        fp->fptr += rcnt, *bf += rcnt, btr -= rcnt) {
        if ((fp->fptr % SS(fp->fs)) == 0) {			/* On the sector boundary? */
            if (fp->csect >= fp->fs->csize) {		/* On the cluster boundary? */
                clst = (fp->fptr == 0) ?			/* On the top of the file? */
                    fp->org_clust : get_fat(fp->fs, fp->curr_clust);
                if (clst <= 1) ABORT(fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
                fp->curr_clust = clst;				/* Update current cluster */
                fp->csect = 0;						/* Reset sector address in the cluster */
            }
            fp->csect++;							/* Next sector address in the cluster */
        }
        sect = clust2sect(fp->fs, fp->curr_clust);	/* Get current data sector */
        if (!sect) ABORT(fp->fs, FR_INT_ERR);
        sect += fp->csect - 1;
        if (move_window(fp->fs, sect))				/* Move sector window */
            ABORT(fp->fs, FR_DISK_ERR);
        fp->dsect = sect;
        rcnt = SS(fp->fs) - (WORD)(fp->fptr % SS(fp->fs));	/* Forward data from sector window */
        if (rcnt > btr) rcnt = btr;
        rcnt = (*func)(&fp->fs->win[(WORD)fp->fptr % SS(fp->fs)], rcnt);
        if (!rcnt) ABORT(fp->fs, FR_INT_ERR);
    }

    LEAVE_FF(fp->fs, FR_OK);
}
#endif /* _USE_FORWARD */



#if _USE_MKFS && !_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Create File System on the Drive                                       */
/*-----------------------------------------------------------------------*/
#define N_ROOTDIR	512			/* Multiple of 32 and <= 2048 */
#define N_FATS		1			/* 1 or 2 */
#define MAX_SECTOR	131072000UL	/* Maximum partition size */
#define MIN_SECTOR	2000UL		/* Minimum partition size */


FRESULT f_mkfs (
    BYTE drv,			/* Logical drive number */
    BYTE partition,		/* Partitioning rule 0:FDISK, 1:SFD */
    WORD allocsize		/* Allocation unit size [bytes] */
)
{
    static const DWORD sstbl[] = { 2048000, 1024000, 512000, 256000, 128000, 64000, 32000, 16000, 8000, 4000,   0 };
    static const WORD cstbl[] =  {   32768,   16384,   8192,   4096,   2048, 16384,  8192,  4096, 2048, 1024, 512 };
    BYTE fmt, m, *tbl;
    DWORD b_part, b_fat, b_dir, b_data;		/* Area offset (LBA) */
    DWORD n_part, n_rsv, n_fat, n_dir;		/* Area size */
    DWORD n_clst, d, n;
    WORD as;
    FATFS *fs;
    DSTATUS stat;


    /* Check validity of the parameters */
    if (drv >= _DRIVES) return FR_INVALID_DRIVE;
    if (partition >= 2) return FR_MKFS_ABORTED;

    /* Check mounted drive and clear work area */
    fs = FatFs[drv];
    if (!fs) return FR_NOT_ENABLED;
    fs->fs_type = 0;
    drv = LD2PD(drv);

    /* Get disk statics */
    stat = disk_initialize(drv);
    if (stat & STA_NOINIT) return FR_NOT_READY;
    if (stat & STA_PROTECT) return FR_WRITE_PROTECTED;
#if _MAX_SS != 512						/* Get disk sector size */
    if (disk_ioctl(drv, GET_SECTOR_SIZE, &SS(fs)) != RES_OK
        || SS(fs) > _MAX_SS)
        return FR_MKFS_ABORTED;
#endif
    if ((disk_ioctl(drv, GET_SECTOR_COUNT, &n_part) != RES_OK) || (n_part < MIN_SECTOR))
        return FR_MKFS_ABORTED;
    if (n_part > MAX_SECTOR) n_part = MAX_SECTOR;
    b_part = (!partition) ? 63 : 0;		/* Boot sector */
    n_part -= b_part;
    for (d = 512; (d <= 32768U) && (d != allocsize); d <<= 1) ;	/* Check validity of the allocation unit size */
    if (d != allocsize) allocsize = 0;
    if (!allocsize) {					/* Auto selection of cluster size */
        d = n_part;
        for (as = SS(fs); as > 512U; as >>= 1) d >>= 1;
        for (n = 0; d < sstbl[n]; n++) ;
        allocsize = cstbl[n];
    }
    if (allocsize < SS(fs)) allocsize = SS(fs);

    allocsize /= SS(fs);		/* Number of sectors per cluster */

    /* Pre-compute number of clusters and FAT type */
    n_clst = n_part / allocsize;
    fmt = FS_FAT12;
    if (n_clst >= 0xFF5) fmt = FS_FAT16;
    if (n_clst >= 0xFFF5) fmt = FS_FAT32;

    /* Determine offset and size of FAT structure */
    switch (fmt) {
    case FS_FAT12:
        n_fat = ((n_clst * 3 + 1) / 2 + 3 + SS(fs) - 1) / SS(fs);
        n_rsv = 1 + partition;
        n_dir = N_ROOTDIR * 32 / SS(fs);
        break;
    case FS_FAT16:
        n_fat = ((n_clst * 2) + 4 + SS(fs) - 1) / SS(fs);
        n_rsv = 1 + partition;
        n_dir = N_ROOTDIR * 32 / SS(fs);
        break;
    default:
        n_fat = ((n_clst * 4) + 8 + SS(fs) - 1) / SS(fs);
        n_rsv = 33 - partition;
        n_dir = 0;
                break;
    }
    b_fat = b_part + n_rsv;			/* FATs start sector */
    b_dir = b_fat + n_fat * N_FATS;	/* Directory start sector */
    b_data = b_dir + n_dir;			/* Data start sector */

    /* Align data start sector to erase block boundary (for flash memory media) */
    if (disk_ioctl(drv, GET_BLOCK_SIZE, &n) != RES_OK) return FR_MKFS_ABORTED;
    n = (b_data + n - 1) & ~(n - 1);
    n_fat += (n - b_data) / N_FATS;
    /* b_dir and b_data are no longer used below */

    /* Determine number of cluster and final check of validity of the FAT type */
    n_clst = (n_part - n_rsv - n_fat * N_FATS - n_dir) / allocsize;
    if (   ((fmt == FS_FAT16) && (n_clst < 0xFF5))
        || ((fmt == FS_FAT32) && (n_clst < 0xFFF5)))
        return FR_MKFS_ABORTED;

    /* Create partition table if needed */
    if (!partition) {
        DWORD n_disk = b_part + n_part;

        mem_set(fs->win, 0, SS(fs));
        tbl = fs->win+MBR_Table;
        ST_DWORD(tbl, 0x00010180);		/* Partition start in CHS */
        if (n_disk < 63UL * 255 * 1024) {	/* Partition end in CHS */
            n_disk = n_disk / 63 / 255;
            tbl[7] = (BYTE)n_disk;
            tbl[6] = (BYTE)((n_disk >> 2) | 63);
        } else {
            ST_WORD(&tbl[6], 0xFFFF);
        }
        tbl[5] = 254;
        if (fmt != FS_FAT32)			/* System ID */
            tbl[4] = (n_part < 0x10000) ? 0x04 : 0x06;
        else
            tbl[4] = 0x0c;
        ST_DWORD(tbl+8, 63);			/* Partition start in LBA */
        ST_DWORD(tbl+12, n_part);		/* Partition size in LBA */
        ST_WORD(tbl+64, 0xAA55);		/* Signature */
        if (disk_write(drv, fs->win, 0, 1) != RES_OK)
            return FR_DISK_ERR;
        partition = 0xF8;
    } else {
        partition = 0xF0;
    }

    /* Create boot record */
    tbl = fs->win;								/* Clear buffer */
    mem_set(tbl, 0, SS(fs));
    ST_DWORD(tbl+BS_jmpBoot, 0x90FEEB);			/* Boot code (jmp $, nop) */
    ST_WORD(tbl+BPB_BytsPerSec, SS(fs));		/* Sector size */
    tbl[BPB_SecPerClus] = (BYTE)allocsize;		/* Sectors per cluster */
    ST_WORD(tbl+BPB_RsvdSecCnt, n_rsv);			/* Reserved sectors */
    tbl[BPB_NumFATs] = N_FATS;					/* Number of FATs */
    ST_WORD(tbl+BPB_RootEntCnt, SS(fs) / 32 * n_dir); /* Number of rootdir entries */
    if (n_part < 0x10000) {						/* Number of total sectors */
        ST_WORD(tbl+BPB_TotSec16, n_part);
    } else {
        ST_DWORD(tbl+BPB_TotSec32, n_part);
    }
    tbl[BPB_Media] = partition;					/* Media descriptor */
    ST_WORD(tbl+BPB_SecPerTrk, 63);				/* Number of sectors per track */
    ST_WORD(tbl+BPB_NumHeads, 255);				/* Number of heads */
    ST_DWORD(tbl+BPB_HiddSec, b_part);			/* Hidden sectors */
    n = get_fattime();							/* Use current time as a VSN */
    if (fmt != FS_FAT32) {
        ST_DWORD(tbl+BS_VolID, n);				/* Volume serial number */
        ST_WORD(tbl+BPB_FATSz16, n_fat);		/* Number of sectors per FAT */
        tbl[BS_DrvNum] = 0x80;					/* Drive number */
        tbl[BS_BootSig] = 0x29;					/* Extended boot signature */
        mem_cpy(tbl+BS_VolLab, "NO NAME    FAT     ", 19);	/* Volume label, FAT signature */
    } else {
        ST_DWORD(tbl+BS_VolID32, n);			/* Volume serial number */
        ST_DWORD(tbl+BPB_FATSz32, n_fat);		/* Number of sectors per FAT */
        ST_DWORD(tbl+BPB_RootClus, 2);			/* Root directory cluster (2) */
        ST_WORD(tbl+BPB_FSInfo, 1);				/* FSInfo record offset (bs+1) */
        ST_WORD(tbl+BPB_BkBootSec, 6);			/* Backup boot record offset (bs+6) */
        tbl[BS_DrvNum32] = 0x80;				/* Drive number */
        tbl[BS_BootSig32] = 0x29;				/* Extended boot signature */
        mem_cpy(tbl+BS_VolLab32, "NO NAME    FAT32   ", 19);	/* Volume label, FAT signature */
    }
    ST_WORD(tbl+BS_55AA, 0xAA55);				/* Signature */
    if (SS(fs) > 512U) {
        ST_WORD(tbl+SS(fs)-2, 0xAA55);
    }
    if (disk_write(drv, tbl, b_part+0, 1) != RES_OK)
        return FR_DISK_ERR;
    if (fmt == FS_FAT32)
        disk_write(drv, tbl, b_part+6, 1);

    /* Initialize FAT area */
    for (m = 0; m < N_FATS; m++) {
        mem_set(tbl, 0, SS(fs));		/* 1st sector of the FAT  */
        if (fmt != FS_FAT32) {
            n = (fmt == FS_FAT12) ? 0x00FFFF00 : 0xFFFFFF00;
            n |= partition;
            ST_DWORD(tbl, n);				/* Reserve cluster #0-1 (FAT12/16) */
        } else {
            ST_DWORD(tbl+0, 0xFFFFFFF8);	/* Reserve cluster #0-1 (FAT32) */
            ST_DWORD(tbl+4, 0xFFFFFFFF);
            ST_DWORD(tbl+8, 0x0FFFFFFF);	/* Reserve cluster #2 for root dir */
        }
        if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
            return FR_DISK_ERR;
        mem_set(tbl, 0, SS(fs));		/* Following FAT entries are filled by zero */
        for (n = 1; n < n_fat; n++) {
            if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
                return FR_DISK_ERR;
        }
    }

    /* Initialize Root directory */
    m = (BYTE)((fmt == FS_FAT32) ? allocsize : n_dir);
    do {
        if (disk_write(drv, tbl, b_fat++, 1) != RES_OK)
            return FR_DISK_ERR;
    } while (--m);

    /* Create FSInfo record if needed */
    if (fmt == FS_FAT32) {
        ST_WORD(tbl+BS_55AA, 0xAA55);
        ST_DWORD(tbl+FSI_LeadSig, 0x41615252);
        ST_DWORD(tbl+FSI_StrucSig, 0x61417272);
        ST_DWORD(tbl+FSI_Free_Count, n_clst - 1);
        ST_DWORD(tbl+FSI_Nxt_Free, 0xFFFFFFFF);
        disk_write(drv, tbl, b_part+1, 1);
        disk_write(drv, tbl, b_part+7, 1);
    }

    return (disk_ioctl(drv, CTRL_SYNC, (void*)NULL) == RES_OK) ? FR_OK : FR_DISK_ERR;
}

#endif /* _USE_MKFS && !_FS_READONLY */




#if _USE_STRFUNC
/*-----------------------------------------------------------------------*/
/* Get a string from the file                                            */
/*-----------------------------------------------------------------------*/
char* f_gets (
    char* buff,	/* Pointer to the string buffer to read */
    int len,	/* Size of string buffer */
    FIL* fil	/* Pointer to the file object */
)
{
    int i = 0;
    char *p = buff;
    UINT rc;


    while (i < len - 1) {			/* Read bytes until buffer gets filled */
        f_read(fil, p, 1, &rc);
        if (rc != 1) break;			/* Break when no data to read */
#if _USE_STRFUNC >= 2
        if (*p == '\r') continue;	/* Strip '\r' */
#endif
        i++;
        if (*p++ == '\n') break;	/* Break when reached end of line */
    }
    *p = 0;
    return i ? buff : NULL;			/* When no data read (eof or error), return with error. */
}



#if !_FS_READONLY
#include <stdarg.h>
/*-----------------------------------------------------------------------*/
/* Put a character to the file                                           */
/*-----------------------------------------------------------------------*/
int f_putc (
    int chr,	/* A character to be output */
    FIL* fil	/* Pointer to the file object */
)
{
    UINT bw;
    char c;


#if _USE_STRFUNC >= 2
    if (chr == '\n') f_putc ('\r', fil);	/* LF -> CRLF conversion */
#endif
    if (!fil) {	/* Special value may be used to switch the destination to any other device */
    /*	put_console(chr);	*/
        return chr;
    }
    c = (char)chr;
    f_write(fil, &c, 1, &bw);	/* Write a byte to the file */
    return bw ? chr : EOF;		/* Return the result */
}




/*-----------------------------------------------------------------------*/
/* Put a string to the file                                              */
/*-----------------------------------------------------------------------*/
int f_puts (
    const char* str,	/* Pointer to the string to be output */
    FIL* fil			/* Pointer to the file object */
)
{
    int n;


    for (n = 0; *str; str++, n++) {
        if (f_putc(*str, fil) == EOF) return EOF;
    }
    return n;
}




/*-----------------------------------------------------------------------*/
/* Put a formatted string to the file                                    */
/*-----------------------------------------------------------------------*/
int f_printf (
    FIL* fil,			/* Pointer to the file object */
    const char* str,	/* Pointer to the format string */
    ...					/* Optional arguments... */
)
{
    va_list arp;
    UCHAR c, f, r;
    ULONG val;
    char s[16];
    int i, w, res, cc;


    va_start(arp, str);

    for (cc = res = 0; cc != EOF; res += cc) {
        c = *str++;
        if (c == 0) break;			/* End of string */
        if (c != '%') {				/* Non escape character */
            cc = f_putc(c, fil);
            if (cc != EOF) cc = 1;
            continue;
        }
        w = f = 0;
        c = *str++;
        if (c == '0') {				/* Flag: '0' padding */
            f = 1; c = *str++;
        }
        while ((c >= '0') && (c <= '9')) {	/* Precision */
            w = w * 10 + (c - '0');
            c = *str++;
        }
        if (c == 'l') {				/* Prefix: Size is long int */
            f |= 2; c = *str++;
        }
        if (c == 's') {				/* Type is string */
            cc = f_puts(va_arg(arp, char*), fil);
            continue;
        }
        if (c == 'c') {				/* Type is character */
            cc = f_putc(va_arg(arp, int), fil);
            if (cc != EOF) cc = 1;
            continue;
        }
        r = 0;
        if (c == 'd') r = 10;		/* Type is signed decimal */
        if (c == 'u') r = 10;		/* Type is unsigned decimal */
        if (c == 'X') r = 16;		/* Type is unsigned hexdecimal */
        if (r == 0) break;			/* Unknown type */
        if (f & 2) {				/* Get the value */
            val = (ULONG)va_arg(arp, long);
        } else {
            val = (c == 'd') ? (ULONG)(long)va_arg(arp, int) : (ULONG)va_arg(arp, unsigned int);
        }
        /* Put numeral string */
        if (c == 'd') {
            if (val & 0x80000000) {
                val = 0 - val;
                f |= 4;
            }
        }
        i = sizeof(s) - 1; s[i] = 0;
        do {
            c = (UCHAR)(val % r + '0');
            if (c > '9') c += 7;
            s[--i] = c;
            val /= r;
        } while (i && val);
        if (i && (f & 4)) s[--i] = '-';
        w = sizeof(s) - 1 - w;
        while (i && (i > w)) s[--i] = (f & 1) ? '0' : ' ';
        cc = f_puts(&s[i], fil);
    }

    va_end(arp);
    return (cc == EOF) ? cc : res;
}

#endif /* !_FS_READONLY */
#endif /* _USE_STRFUNC */
